Digital SAT Math Practice Questions

Digital SAT Math Practice

Practice SAT Math by Skill

Build Digital SAT Math skills with a targeted diagnostic, answer explanations, calculator strategy, and practice by topic. Start with the diagnostic to identify weak areas, then review Algebra, Advanced Math, Problem-Solving and Data Analysis, Geometry and Trigonometry, or Calculator Strategy.

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Question 1 of 29
SAT Math Skill Bank

Choose a Math Skill to Review

A

Algebra

Linear equations, inequalities, systems, slope, and linear models.

Linear Equations and Expression Targets
MentalAlgebra
Overview
Linear-equation questions ask students to isolate a value, transform an equation, or solve for a requested expression. On the SAT, the fastest route is often not solving for x, but solving directly for the expression the question asks about.
SAT Math Strategy Guide
Expression targetIf the question asks for px + q, try creating px + q directly instead of solving for x.
FractionsClear fractions first by multiplying every term by the least common denominator.
No-solution checkFor ax + b = cx + d, no solution means the x-coefficients match but constants differ.
What the SAT tests
  • one-variable linear equations
  • fractions and signs
  • expression targets
  • parameter values
  • recognizing when solving for x is unnecessary
Practice this skill

These questions build from foundation to SAT-style difficulty. Try each one before revealing the solution.

Easyexpression targetMultiple choice

1. If 5x + 7 = 32, what is the value of 10x + 14?

  1. 50
  2. 57
  3. 64
  4. 71
Show solution
Answer: C. 64
Answer Explanation

Choice C is correct because 10x + 14 is exactly 2(5x + 7). Since 5x + 7 = 32, doubling gives 64.

Fastest Route

Double the given expression: 2(32)=64.

Best Tool

Mental

Why This Route Is Fast

The target expression is a multiple of the expression already given.

Desmos Note

Not needed.

Common Trap

Solving for x first, which works but takes longer.

Final Answer

C. 64

MediumfractionsStudent-produced response

2. If (2x − 5)/3 + (x + 4)/2 = 7, what is the value of x?

Student-produced response
Show solution
Answer: 40/7
Answer Explanation

Multiplying every term by 6 gives 2(2x − 5) + 3(x + 4) = 42, which simplifies to 7x + 2 = 42.

Fastest Route

Clear denominators first, then solve: 7x = 40, so x = 40/7.

Best Tool

Algebra

Why This Route Is Fast

Clearing fractions turns the equation into a standard linear equation.

Desmos Note

Not needed.

Common Trap

Multiplying only the fractions by 6 instead of every term.

Final Answer

40/7

Very Hardno solutionStudent-produced response

3. The equation p(3x − 2) − q(x + 5) = 20x − 14 has no solution. If p − q = 6, what is q?

Student-produced response
Show solution
Answer: 1
Answer Explanation

The correct answer is 1. Expanding the left side gives an x-coefficient of 3p − q. For no solution, that coefficient must equal 20, while the constants are different.

Fastest Route

Use 3p − q = 20 and p − q = 6. Substitute p=q+6: 3(q+6)−q=20, so 2q+18=20 and q=1.

Best Tool

Algebra

Why This Route Is Fast

Coefficient matching is faster than trying to solve a parameterized equation for x.

Desmos Note

Not needed.

Common Trap

Forgetting that no solution requires equal x-coefficients but different constants.

Final Answer

1

Linear Inequalities and Constraint Ranges
AlgebraBoundary valuesEndpoint checking
Overview
Inequalities describe ranges of values. SAT inequality items often test endpoint awareness, integer counts, and whether an inequality sign flips.
SAT Math Strategy Guide
Sign ruleMultiplying or dividing by a negative reverses the inequality sign.
Integer countsSolve the interval first, then count the allowed integers using endpoints carefully.
Boundary moveWhen a solution set has an endpoint, plug the endpoint into the equality version.
What the SAT tests
  • solving one-variable inequalities
  • compound inequalities
  • integer solution counts
  • inclusive vs. exclusive endpoints
  • least/greatest integer satisfying a condition
  • parameter values tied to a boundary
Practice this skill

These questions build from foundation to SAT-style difficulty. Try each one before revealing the solution.

Mediumcompound intervalStudent-produced response

1. How many integer values of x satisfy −3 ≤ (x + 5)/2 < 6?

Student-produced response
Show solution
Answer: 18
Answer Explanation

The inequality simplifies to −11 ≤ x < 7, so the integers are −11 through 6.

Fastest Route

Multiply all parts by 2, then subtract 5: −6 ≤ x+5 < 12, so −11 ≤ x < 7. Count from −11 to 6.

Best Tool

Algebra

Why This Route Is Fast

Solving the interval first makes the integer count direct.

Desmos Note

Not needed.

Common Trap

Including 7 even though the right endpoint is open.

Final Answer

18

Hardparameter boundaryStudent-produced response

2. For what integer value of a is x = 4 not a solution of 2x + a ≥ 3a − 1, but x = 5 is a solution?

Student-produced response
Show solution
Answer: 5
Answer Explanation

The correct answer is 5. Testing the two boundary values gives a > 4.5 and a ≤ 5.5, so the only integer is 5.

Fastest Route

Plug in x = 4 and require the inequality to be false. Plug in x = 5 and require it to be true. Combine the restrictions.

Best Tool

Boundary value

Why This Route Is Fast

Testing the named values is faster than solving for the entire solution set first.

Desmos Note

Not needed.

Common Trap

Treating “not a solution” as if the inequality should still hold.

Final Answer

5

Hardboundary valueMultiple choice

3. For what value of k is the solution set of 7 − 3x ≥ kx + 1 equal to x ≤ 2?

  1. −2
  2. 0
  3. 2
  4. 4
Show solution
Answer: B. 0
Answer Explanation

If the solution set is x ≤ 2, then x=2 is the boundary where equality holds. Substituting gives k=0.

Fastest Route

Use the equality at the boundary: 7−3(2)=2k+1. This gives 1=2k+1, so k=0.

Best Tool

Boundary value / Algebra

Why This Route Is Fast

The endpoint gives the parameter without solving the full inequality first.

Desmos Note

Not useful here.

Common Trap

Forgetting that the boundary value must make both sides equal.

Final Answer

B. 0

Linear Functions, Slope, and Intercepts
Mental rate of changeAlgebraDesmos Table when checking values
Overview
Linear functions describe constant rate of change. SAT items often move between points, tables, intercepts, equations, and contextual rates.
SAT Math Strategy Guide
Slopem = (y2 − y1)/(x2 − x1)
Interceptsx-intercept: set y = 0; y-intercept: set x = 0.
Step from a known pointUse rate × input change instead of writing the whole equation when possible.
What the SAT tests
  • slope from two points
  • y-intercept and x-intercept
  • writing a linear function
  • interpreting rate of change
  • stepping from a known point instead of building a full equation
  • parallel and perpendicular slope
Practice this skill

These questions build from foundation to SAT-style difficulty. Try each one before revealing the solution.

Basicslope from pointsMultiple choice

1. A line passes through (−3, 7) and (5, −9). What is the slope of the line?

  1. −4
  2. −2
  3. 1/2
  4. 2
Show solution
Answer: B. −2
Answer Explanation

The change in y is −9 − 7 = −16 and the change in x is 5 − (−3) = 8. The slope is −16/8 = −2.

Fastest Route

Use rise over run directly from the two points.

Best Tool

Mental / Algebra

Why This Route Is Fast

The coordinate differences are small enough to compute quickly.

Desmos Note

Not needed.

Common Trap

Subtracting coordinates in inconsistent order.

Final Answer

B. −2

Mediumrate of changeMultiple choice

2. A linear function h satisfies h(3)=14 and h(9)=38. What is h(12)?

  1. 42
  2. 46
  3. 50
  4. 54
Show solution
Answer: C. 50
Answer Explanation

Choice C is correct. The output increases by 24 when the input increases by 6, so the rate is 4. From 9 to 12 is 3 input units, so the output increases by 12.

Fastest Route

Compute the rate: (38−14)/(9−3)=4. Then h(12)=38+4(3)=50.

Best Tool

Mental

Why This Route Is Fast

Stepping from a known point avoids writing the full equation.

Desmos Note

Not needed.

Common Trap

Using the rate once instead of for each input step.

Final Answer

C. 50

Very Hardhidden intersectionStudent-produced response

3. In the xy-plane, the line y = mx + b passes through (4, 1). It intersects y = 2x − 5 at a point whose x-coordinate is twice its y-coordinate. What is m?

Student-produced response
Show solution
Answer: −1
Answer Explanation

The correct answer is −1. The intersection point is (10/3, 5/3), and the slope through that point and (4,1) is −1.

Fastest Route

Use x = 2y, so y = x/2. Set x/2 = 2x − 5 to get x=10/3 and y=5/3. Then compute the slope from (4,1) to that point.

Best Tool

Algebra

Why This Route Is Fast

Finding the intersection first keeps the problem linear and exact.

Desmos Note

Not needed.

Common Trap

Trying to use m before finding the actual intersection point.

Final Answer

−1

Systems of Linear Equations
AlgebraCoefficient matchingElimination
Overview
A system asks for values that satisfy two equations at once. SAT systems often ask for an expression, a parameter, or the number of solutions.
SAT Math Strategy Guide
EliminationAdd or subtract equations when coefficients already line up.
No solutionParallel distinct lines: matching slopes but different intercepts.
Infinite solutionsOne equation is an exact multiple of the other.
What the SAT tests
  • elimination
  • substitution
  • expression targets
  • no solution
  • infinitely many solutions
  • system interpretation
  • parallel distinct lines
Practice this skill

These questions build from foundation to SAT-style difficulty. Try each one before revealing the solution.

MediumeliminationMultiple choice

1. If 3x + y = 16 and x − y = 4, what is 2x + y?

  1. 9
  2. 11
  3. 13
  4. 16
Show solution
Answer: B. 11
Answer Explanation

Choice B is correct. Adding the equations gives 4x=20, so x=5. Then y=1 and 2x+y=11.

Fastest Route

Add the equations to eliminate y immediately, then substitute into either equation.

Best Tool

Algebra

Why This Route Is Fast

The y-terms cancel without rearranging either equation.

Desmos Note

Not needed.

Common Trap

Stopping after finding x instead of answering the requested expression.

Final Answer

B. 11

Mediumparallel linesMultiple choice

2. For what value of k does the system kx + 4y = 7 and 6x + 8y = 20 have no solution?

  1. 2
  2. 3
  3. 4
  4. 6
Show solution
Answer: B. 3
Answer Explanation

To make the y-coefficients match, double the first equation. The x-coefficient must also double, so 2k=6 and k=3. The constants become 14 and 20, so the lines are distinct.

Fastest Route

Match coefficients and check that the constants do not match.

Best Tool

Coefficient comparison

Why This Route Is Fast

No-solution systems usually reduce to parallel but distinct lines.

Desmos Note

Not needed.

Common Trap

Forgetting to check that the constants are different.

Final Answer

B. 3

Very Hardno solution parameterStudent-produced response

3. For some constant k, the system below has no solution: (2k − 1)x + 3y = 7
4x + (k + 2)y = 10
What is the sum of all possible values of k?

Student-produced response
Show solution
Answer: 3/2
Answer Explanation

The correct answer is −3/2. No solution requires the coefficient rows to be proportional, so the determinant must be 0. The resulting quadratic has root sum −3/2.

Fastest Route

Set the determinant to 0: (2k−1)(k+2)−12=0, which simplifies to 2k2+3k−14=0. The sum of roots is −b/a = −3/2.

Best Tool

Algebra

Why This Route Is Fast

Vieta’s sum avoids solving for both k-values separately.

Desmos Note

Not needed.

Common Trap

Solving for one k-value and forgetting the question asks for the sum of all possible values.

Final Answer

−3/2

Very Hardinfinite solutionsStudent-produced response

4. A system of two linear equations has infinitely many solutions. One equation is 3x − 2y = 12. The other equation is ax − 8y = b. What is the value of a + b?

Student-produced response
Show solution
Answer: 60
Answer Explanation

For infinitely many solutions, the second equation must be an exact multiple of the first equation.

Fastest Route

Since −8y is 4 times −2y, multiply the entire first equation by 4: 12x − 8y = 48. Therefore, a=12, b=48, and a+b=60.

Best Tool

Coefficient matching

Why This Route Is Fast

Infinite-solution systems require every coefficient and constant to scale by the same factor.

Desmos Note

Not useful for symbolic parameters.

Common Trap

Matching only the y-coefficient and forgetting to scale the constant term too.

Final Answer

60

Linear Models and Word Problems
AlgebraUnitsInequality direction
Overview
Linear word problems describe a starting value plus a constant rate. Students must identify whether the question asks for input, output, rate, difference, or threshold.
SAT Math Strategy Guide
Linear modeloutput = starting value + rate × input
Break-evenSet the two models equal; use < or > carefully for threshold questions.
UnitsAttach units to every slope so the model has meaning.
What the SAT tests
  • model setup
  • fixed fee and rate
  • comparing two plans
  • break-even points
  • least/greatest whole number
  • linear projection over time
Practice this skill

These questions build from foundation to SAT-style difficulty. Try each one before revealing the solution.

Easyfixed feeStudent-produced response

1. A printing company charges a fixed fee plus a constant amount per poster. The cost is $115 for 20 posters and $175 for 35 posters. What is the fixed fee, in dollars?

Student-produced response
Show solution
Answer: 35
Answer Explanation

The correct answer is 35. The cost increases $60 for 15 posters, so the rate is $4 per poster. Using 20 posters gives a fixed fee of $35.

Fastest Route

Compute the rate: (175−115)/(35−20)=4. Then 115 = fixed fee + 4(20), so the fixed fee is 35.

Best Tool

Algebra

Why This Route Is Fast

Two points reveal the rate quickly, then one point gives the intercept.

Desmos Note

Not needed.

Common Trap

Using 115 as the fixed fee instead of subtracting the variable cost.

Final Answer

35

Easyfixed fee and rateMultiple choice

2. A service charges a setup fee of $18 and $3.50 for each unit. If the total charge is $74, how many units were purchased?

  1. 14
  2. 15
  3. 16
  4. 18
Show solution
Answer: C. 16
Answer Explanation

The model is 74 = 18 + 3.50u. Subtract 18 to get 56, then divide by 3.50 to get 16.

Fastest Route

Remove the fixed fee first, then divide by the unit rate.

Best Tool

Algebra

Why This Route Is Fast

The setup fee happens once, so subtracting it isolates the repeated cost.

Desmos Note

Not needed.

Common Trap

Multiplying the setup fee by the number of units.

Final Answer

C. 16

Hardthreshold inequalityStudent-produced response

3. Plan A charges $50 plus $0.10 per minute. Plan B charges $26 plus $0.16 per minute. What is the least whole number of minutes for which Plan A costs less than Plan B?

Student-produced response
Show solution
Answer: 401
Answer Explanation

The plans are equal at 400 minutes, so Plan A is less expensive only for whole-number minutes greater than 400.

Fastest Route

Solve 50 + 0.10m < 26 + 0.16m. This gives 24 < 0.06m, so 400 < m. The least whole number is 401.

Best Tool

Algebra

Why This Route Is Fast

This is a threshold question; solve the inequality and round up.

Desmos Note

Graphing can verify the break-even point, but hand-solving is faster.

Common Trap

Answering 400, where the costs are equal.

Final Answer

401

Very Hardlinear projectionStudent-produced response

4. A company had 1,240 members in 2022 and 1,720 members in 2026. The number of members increased linearly. According to this model, in what year will the company first have at least 2,000 members?

Student-produced response
Show solution
Answer: 2029
Answer Explanation

The correct answer is 2029. The increase is 480 members over 4 years, or 120 per year. The model first reaches at least 2,000 members 7 years after 2022.

Fastest Route

Use 1240 + 120t ≥ 2000. Then 120t ≥ 760, so t ≥ 19/3. The first whole year is t=7, which is 2029.

Best Tool

Algebra

Why This Route Is Fast

Threshold questions require rounding up to the first whole input that satisfies the inequality.

Desmos Note

Not needed.

Common Trap

Rounding 6.33 down and choosing 2028, which is still below 2,000.

Final Answer

2029

ƒ

Advanced Math

Quadratics, nonlinear equations, functions, equivalent expressions, and exponential/rational patterns.

Quadratics: Zeros, Vertex, and Discriminant
AlgebraVietaSymmetryDesmos only for messy graph features
Overview
Quadratic questions involve parabolas, zeros, vertex, symmetry, and equivalent forms. The SAT often rewards structure over expansion.
SAT Math Strategy Guide
Intercept formf(x)=a(x−r)(x−s) when zeros are known.
Vieta’s formulasFor ax2 + bx + c = 0: root sum = b/a; root product = c/a.
AxisThe vertex x-value is halfway between the zeros.
Discriminantb2−4ac tells how many real roots a quadratic has.
What the SAT tests
  • factoring
  • intercept form
  • vertex form
  • axis of symmetry
  • discriminant
  • minimum/maximum value
  • Vieta’s formulas
  • parameter values producing one/two/no real solutions
Practice this skill

These questions build from foundation to SAT-style difficulty. Try each one before revealing the solution.

BasicVieta sumMultiple choice

1. For the equation 3x2 − 18x + 5 = 0, what is the sum of the two solutions?

  1. −6
  2. 5/3
  3. 6
  4. 18
Show solution
Answer: C. 6
Answer Explanation

For ax2 + bx + c = 0, the sum of roots is b/a. Here a=3 and b=−18, so the sum is 6.

Fastest Route

Use Vieta’s formula instead of solving the quadratic.

Best Tool

Mental / Algebra

Why This Route Is Fast

The question asks only for the sum, not the roots.

Desmos Note

Not needed.

Common Trap

Using c/a, which gives the product, not the sum.

Final Answer

C. 6

Hardintercept formMultiple choice

2. A quadratic function has zeros 2 and 10 and passes through (0, 80). What is its minimum value?

  1. −80
  2. −64
  3. −48
  4. 64
Show solution
Answer: B. −64
Answer Explanation

Choice B is correct. The function is f(x)=4(x−2)(x−10). The axis is x=6 and f(6)=−64.

Fastest Route

Use intercept form. Since 80=a(−2)(−10)=20a, a=4. Evaluate the midpoint of the zeros: x=6.

Best Tool

Algebra

Why This Route Is Fast

Zeros make intercept form and symmetry faster than expanding.

Desmos Note

Not needed.

Common Trap

Using one zero as the vertex instead of the midpoint between the zeros.

Final Answer

B. −64

Hardintercept form and vertexMultiple choice

3. A quadratic function has zeros −1 and 5 and passes through (0, −15). What is its minimum value?

  1. −36
  2. −27
  3. −18
  4. 27
Show solution
Answer: B. −27
Answer Explanation

The function is f(x)=3(x+1)(x−5). The axis is halfway between the zeros at x=2, and f(2)=−27.

Fastest Route

Use intercept form and find a: −15=a(1)(−5), so a=3. Then evaluate at the midpoint of −1 and 5.

Best Tool

Algebra

Why This Route Is Fast

The zeros immediately reveal the useful form.

Desmos Note

Desmos can verify, but exact algebra is cleaner.

Common Trap

Using the y-intercept as the minimum value.

Final Answer

B. −27

Very Hardsymmetry and valueStudent-produced response

4. A quadratic function f satisfies f(4)=0, has axis of symmetry x = 5/2, and f(2)=6. If f(x)=ax2+bx+c, what is c?

Student-produced response
Show solution
Answer: −12
Answer Explanation

The correct answer is −12. The root 4 reflects across the axis x=5/2 to root 1, so f(x)=a(x−4)(x−1).

Fastest Route

Use f(2)=6: 6=a(−2)(1), so a=−3. Then c=f(0)=−3(−4)(−1)=−12.

Best Tool

Algebra

Why This Route Is Fast

The axis reveals the second zero immediately.

Desmos Note

Not needed.

Common Trap

Trying to expand before using symmetry.

Final Answer

−12

Very Hardvertex formStudent-produced response

5. A quadratic function has vertex (3, −8) and passes through (5, 4). If the function is written as f(x)=a(x−3)2−8, what is the value of a?

Student-produced response
Show solution
Answer: 3
Answer Explanation

The vertex form is already given, so substitute the point (5,4).

Fastest Route

Use 4=a(5−3)2−8. Then 4=4a−8, so 12=4a and a=3.

Best Tool

Algebra

Why This Route Is Fast

Vertex form lets you substitute directly without expanding.

Desmos Note

Not needed.

Common Trap

Forgetting to add 8 before dividing by 4.

Final Answer

3

Equivalent Expressions and Structure
AlgebraStructure recognition
Overview
Equivalent-expression questions ask students to rewrite without changing value. High-score SAT items often use factoring to reveal a coefficient, zero, restriction, or hidden expression.
SAT Math Strategy Guide
Difference of squaresa2 − b2 = (a−b)(a+b)
Perfect squarea2 ± 2ab + b2 = (a±b)2
RestrictionsRecord excluded values before canceling factors.
What the SAT tests
  • factoring
  • expanding
  • simplifying rational expressions
  • equivalent forms
  • restrictions
  • coefficient matching
  • forms that reveal features
Practice this skill

These questions build from foundation to SAT-style difficulty. Try each one before revealing the solution.

Basicdifference of squaresMultiple choice

1. Which expression is equivalent to (x − 5)2 − 9?

  1. (x − 8)(x − 2)
  2. (x − 14)(x + 4)
  3. x2 − 25
  4. x2 − 10x + 34
Show solution
Answer: A. (x − 8)(x − 2)
Answer Explanation

This is a difference of squares: (x−5)2 − 32. It factors to (x−5−3)(x−5+3).

Fastest Route

Use the difference-of-squares pattern before expanding.

Best Tool

Mental / Algebra

Why This Route Is Fast

Factoring the structure is faster than full expansion.

Desmos Note

Not needed.

Common Trap

Expanding first and making a sign error.

Final Answer

A. (x − 8)(x − 2)

Mediumrational simplificationMultiple choice

2. For x ≠ −2, the expression (x2 − 4)/(x2 + 4x + 4) is evaluated at x = 8. What is the value?

  1. 1/3
  2. 3/5
  3. 5/3
  4. 5
Show solution
Answer: B. 3/5
Answer Explanation

Factoring simplifies the expression to (x−2)/(x+2). At x=8, this is 6/10 = 3/5.

Fastest Route

Factor first: x2−4=(x−2)(x+2) and x2+4x+4=(x+2)2. Then substitute.

Best Tool

Algebra

Why This Route Is Fast

Factoring before substituting avoids larger arithmetic.

Desmos Note

Not needed.

Common Trap

Canceling terms instead of factors.

Final Answer

B. 3/5

Mediumrational simplificationMultiple choice

3. For x ≠ −4, which expression is equivalent to (x2 + 7x + 12)/(x + 4)?

  1. x + 3
  2. x + 4
  3. x + 7
  4. x2 + 3
Show solution
Answer: A. x + 3
Answer Explanation

The numerator factors as (x+3)(x+4). Since x≠−4, the factor x+4 can be canceled.

Fastest Route

Factor first, cancel only the common factor, and keep the restriction in mind.

Best Tool

Algebra

Why This Route Is Fast

Factoring exposes the cancellation immediately.

Desmos Note

Not needed.

Common Trap

Canceling terms instead of factors.

Final Answer

A. x + 3

Very Hardcoefficient matchingStudent-produced response

4. For x ≠ −3, (x2 + (a + 3)x + 3a)/(x + 3) = x + 5 for all allowed values of x. What is a?

Student-produced response
Show solution
Answer: 5
Answer Explanation

The correct answer is 5. For the quotient to be x+5, the numerator must equal (x+3)(x+5).

Fastest Route

Expand (x+3)(x+5)=x2+8x+15. Compare with x2+(a+3)x+3a. Then a+3=8 and 3a=15, so a=5.

Best Tool

Algebra

Why This Route Is Fast

Matching the target structure is faster than long division.

Desmos Note

Not needed.

Common Trap

Canceling without making the numerator match the denominator times the quotient.

Final Answer

5

Nonlinear Equations and Systems
Algebra for exact symbolic problemsDesmos for ugly approximate intersections
Overview
Nonlinear equations include quadratics, radicals, rational equations, and systems involving curves. Students should choose between factoring, squaring, restrictions, and graphing.
SAT Math Strategy Guide
RadicalsIf you square both sides, check the answer in the original equation.
RestrictionsDenominators cannot be zero, and even-root radicands must be nonnegative.
IntersectionsSet equations equal; exactly one intersection often means discriminant 0.
What the SAT tests
  • solving quadratic equations
  • radical equations
  • rational equations
  • extraneous solutions
  • number of intersections
  • tangent/repeated-root conditions
  • nonlinear systems
Practice this skill

These questions build from foundation to SAT-style difficulty. Try each one before revealing the solution.

Easyradical equationStudent-produced response

1. If x + 5 = x − 1, what is x?

Student-produced response
Show solution
Answer: 4
Answer Explanation

Squaring gives x+5=(x−1)2, which simplifies to (x−4)(x+1)=0. Only x=4 satisfies the original equation.

Fastest Route

Check the domain, square both sides, then verify the candidates.

Best Tool

Algebra

Why This Route Is Fast

The radical is isolated, so squaring is direct.

Desmos Note

Not needed.

Common Trap

Keeping the extraneous solution x = −1.

Final Answer

4

Mediumrational equationStudent-produced response

2. The positive solution to (x + 6)/x = 5 is r. What is r2 − r?

Student-produced response
Show solution
Answer: 3/4
Answer Explanation

Multiply by x to get x+6=5x, so x=3/2. Then r2−r = 9/46/4 = 3/4.

Fastest Route

Solve for r first, then compute the requested expression.

Best Tool

Algebra

Why This Route Is Fast

The equation becomes linear after clearing the denominator.

Desmos Note

Not needed.

Common Trap

Returning r instead of r² − r.

Final Answer

3/4

Hardradical equationStudent-produced response

3. If x + 16x = 2 and x > 0, what is x?

Student-produced response
Show solution
Answer: 9
Answer Explanation

The correct answer is 9 because 259 = 5−3 = 2.

Fastest Route

Use Desmos or isolate and square carefully, then verify in the original equation.

Best Tool

Desmos Graph or Algebra

Why This Route Is Fast

Graphing avoids common radical-squaring errors and quickly confirms the solution.

Desmos Note

Graph y = sqrt(x + 16) - sqrt(x) and y = 2; read the x-coordinate of the intersection.

Common Trap

Squaring without checking the result in the original equation.

Final Answer

9

HarddiscriminantMultiple choice

4. The graphs of y = x2 + kx + 9 and y = 4x + 5 intersect at exactly one point. What is the product of all possible values of k?

  1. −16
  2. 0
  3. 8
  4. 16
Show solution
Answer: B. 0
Answer Explanation

Setting the equations equal gives x2 + (k−4)x + 4 = 0. Exactly one solution means the discriminant is 0, which gives possible values k=0 and k=8. Their product is 0.

Fastest Route

Use (k−4)2−16=0, so k−4=±4.

Best Tool

Algebra

Why This Route Is Fast

A tangent line to a parabola becomes a quadratic with discriminant 0.

Desmos Note

Not needed.

Common Trap

Thinking exactly one intersection means there is only one possible k-value.

Final Answer

B. 0

Nonlinear Functions: Features, Graphs, and Models
Desmos Graph for extrema/intersectionsAlgebra when form reveals the feature
Overview
Nonlinear-function questions test graph features, zeros, y-intercepts, vertex/minimum/maximum, exponential models, and interpreting constants.
SAT Math Strategy Guide
ExtremaGraph features are often fastest in Desmos when the expression is messy.
DistanceMinimize distance squared to avoid an unnecessary square root.
ModelsRead the requested input/output carefully; do not report the wrong coordinate.
What the SAT tests
  • nonlinear function features
  • zeros
  • intercepts
  • minimum and maximum values
  • interpreting constants
  • comparing graph/table/equation
  • exponential growth/decay
  • function features in context
Practice this skill

These questions build from foundation to SAT-style difficulty. Try each one before revealing the solution.

Mediumgrowth modelStudent-produced response

1. A population is modeled by P(t)=600(1.25)t, where t is years after 2020. What population does the model predict for 2022?

Student-produced response
Show solution
Answer: 937.5
Answer Explanation

The correct answer is 937.5. Since 2022 is 2 years after 2020, evaluate P(2).

Fastest Route

Compute 600(1.25)2 = 600(1.5625)=937.5.

Best Tool

Algebra

Why This Route Is Fast

Substituting the correct input is faster than making a table.

Desmos Note

Not needed.

Common Trap

Using t = 2022 instead of t = 2.

Final Answer

937.5

Mediumvertex formMultiple choice

2. What is the minimum value of f(x) = (x − 3)2 + 7?

  1. 3
  2. 7
  3. 9
  4. 16
Show solution
Answer: B. 7
Answer Explanation

The squared term (x−3)2 is never negative. Its smallest value is 0, so the smallest output is 7.

Fastest Route

Read the vertex form directly.

Best Tool

Mental

Why This Route Is Fast

No expansion or graphing is needed when the vertex is visible.

Desmos Note

Not needed.

Common Trap

Reporting the x-value 3 instead of the minimum y-value 7.

Final Answer

B. 7

Mediumexponential modelStudent-produced response

3. A quantity is modeled by P(t)=800(1.06)t. By what percent does it increase each time t increases by 1?

Student-produced response
Show solution
Answer: 6
Answer Explanation

The multiplier 1.06 means 1 + 0.06, so the growth rate is 6%.

Fastest Route

Subtract 1 from the growth factor and convert to a percent.

Best Tool

Mental

Why This Route Is Fast

The growth factor directly encodes the percent increase.

Desmos Note

Not needed.

Common Trap

Saying 106% instead of a 6% increase.

Final Answer

6

Very Hardminimum distanceMultiple choice

4. For positive t, the point (t, 20/t) lies on xy = 20. For what value of t is the distance from this point to the origin minimized?

  1. 10
  2. 4
  3. 25
  4. 52
Show solution
Answer: C. 25
Answer Explanation

The distance is minimized at the same t-value that minimizes t2 + 400/t2. This occurs when t = 20/t, so t2=20.

Fastest Route

Graph y = x2 + (20/x)2 for x > 0 and read the x-coordinate of the minimum, or reason by symmetry.

Best Tool

Desmos Graph

Why This Route Is Fast

The squared-distance expression has the same minimizing input as distance.

Desmos Note

Graph y = x^2 + (20/x)^2 with x > 0; read the x-coordinate of the minimum.

Common Trap

Reporting the minimum y-value instead of the x-value.

Final Answer

C. 25

Exponents, Radicals, and Rational Expressions
AlgebraDesmos when radical/rational solutions are messy and numeric
Overview
This skill covers exponent rules, common bases, radicals, rational expressions, restrictions, and growth/decay factors.
SAT Math Strategy Guide
Power rulesaman=am+n and (am)n=amn.
Common baseRewrite powers with the same base before setting exponents equal.
Rational equationsState denominator restrictions before multiplying through.
What the SAT tests
  • exponent rules
  • common-base equations
  • radical equations
  • rational expressions
  • restrictions
  • equivalent forms
  • interpreting growth/decay factors
Practice this skill

These questions build from foundation to SAT-style difficulty. Try each one before revealing the solution.

Mediumcommon baseMultiple choice

1. If 4x + 2 = 82x − 1, what is x?

  1. 5/4
  2. 7/4
  3. 9/4
  4. 3
Show solution
Answer: B. 7/4
Answer Explanation

Rewrite both sides with base 2: 22x+4 = 26x−3, so 2x+4=6x−3.

Fastest Route

Solve 7=4x, so x=7/4.

Best Tool

Algebra

Why This Route Is Fast

Common-base rewriting turns the exponential equation into a linear equation.

Desmos Note

Not needed.

Common Trap

Multiplying the exponent on 8 incorrectly.

Final Answer

B. 7/4

Mediumcommon baseMultiple choice

2. If 16x−1 = 8x+2, what is x?

  1. 6
  2. 8
  3. 10
  4. 12
Show solution
Answer: C. 10
Answer Explanation

Rewrite both sides with base 2: 24x−4 = 23x+6. Therefore 4x−4=3x+6 and x=10.

Fastest Route

Use common bases, then equate exponents.

Best Tool

Algebra

Why This Route Is Fast

The bases are powers of 2, so the equation becomes linear.

Desmos Note

Not necessary.

Common Trap

Forgetting to distribute the exponent across the base conversion.

Final Answer

C. 10

Mediumrational function valueStudent-produced response

3. If h(x)=((x−2)2 + 5)/(x + 3), what is h(7)?

Student-produced response
Show solution
Answer: 3
Answer Explanation

Substitute x=7: the numerator is (5)2+5=30 and the denominator is 10, so h(7)=3.

Fastest Route

Substitute 7 with grouped numerator and denominator.

Best Tool

Algebra or Desmos Table

Why This Route Is Fast

Only one input value is needed.

Desmos Note

A table works well if the expression is entered with parentheses around the whole numerator and denominator.

Common Trap

Typing the expression without grouping the fraction.

Final Answer

3

Hardrational equationStudent-produced response

4. If x ≠ 3 and (2x + 5)/(x − 3) = 4, what is x?

Student-produced response
Show solution
Answer: 17/2
Answer Explanation

Multiply both sides by x−3, which is allowed because x ≠ 3.

Fastest Route

2x+5=4(x−3), so 2x+5=4x−12. Then 17=2x, so x=17/2.

Best Tool

Algebra

Why This Route Is Fast

Clearing the denominator turns the rational equation into a linear equation.

Desmos Note

Not needed.

Common Trap

Multiplying only one side by the denominator or ignoring the restriction.

Final Answer

17/2

Hardradical equationStudent-produced response

5. If x + 25x = 1 and x > 0, what is x?

Student-produced response
Show solution
Answer: 144
Answer Explanation

x=144 works because 169144 = 13 − 12 = 1.

Fastest Route

Use Desmos or square carefully after isolating one radical, then verify.

Best Tool

Desmos Graph or Algebra

Why This Route Is Fast

Graphing is efficient for radical equations with a clean numeric intersection.

Desmos Note

Graph y = sqrt(x + 25) - sqrt(x) and y = 1; read the x-coordinate of the intersection.

Common Trap

Squaring and keeping an extraneous value.

Final Answer

144

Function Notation, Composition, and Transformations
MentalAlgebraDesmos tables when useful
Overview
Function questions test inputs, outputs, composition, shifted inputs, and transformations. The key is matching the requested input or output exactly.
SAT Math Strategy Guide
Function notationf(a) means the output when the input is a.
CompositionWork from the inside out.
TransformationsOutside changes affect y-values directly; negative multipliers reverse max/min behavior.
What the SAT tests
  • f(a)
  • f(g(x))
  • shifted inputs such as f(x+k)
  • transformed function values
  • graph shifts
  • reflections
  • max/min changes after vertical transformations
Practice this skill

These questions build from foundation to SAT-style difficulty. Try each one before revealing the solution.

MediumcompositionStudent-produced response

1. If f(x)=x2−4 and g(x)=3x+1, what is f(g(2))?

Student-produced response
Show solution
Answer: 45
Answer Explanation

First g(2)=7. Then f(7)=72−4=45.

Fastest Route

Work from the inside out.

Best Tool

Mental / Algebra

Why This Route Is Fast

Composition becomes two simple evaluations.

Desmos Note

Not needed.

Common Trap

Plugging 2 directly into f instead of into g first.

Final Answer

45

Hardshifted inputStudent-produced response

2. For all x, f(3x + 2) = x2 − x What is f(14)?

Student-produced response
Show solution
Answer: 12
Answer Explanation

To find f(14), the input 3x+2 must equal 14, so x=4. Then x2−x=16−4=12.

Fastest Route

Set 3x+2=14, solve for x=4, and substitute into the right side.

Best Tool

Algebra

Why This Route Is Fast

Matching the input of f prevents substituting 14 into the wrong expression.

Desmos Note

Not needed.

Common Trap

Calculating 14² − 14 as if 14 were x.

Final Answer

12

Hardtransformation extremumStudent-produced response

3. The minimum point of y = f(x) is (−1, 5). The function g is defined by g(x) = −2f(x − 4) + 3 What is the maximum y-value of g?

Student-produced response
Show solution
Answer: −7
Answer Explanation

The correct answer is −7. The minimum output of f is 5. The outside transformation sends that output to −2(5)+3=−7. Because the multiplier is negative, the original minimum becomes a maximum.

Fastest Route

Ignore the horizontal shift for the y-value. Transform the output 5: −2(5)+3=−7.

Best Tool

Mental / Transformation reasoning

Why This Route Is Fast

The input shift changes where the point occurs, not the transformed output value.

Desmos Note

Not needed.

Common Trap

Calling −7 the minimum instead of the maximum.

Final Answer

−7

Hardshifted inputStudent-produced response

4. For all x, f(2x + 3) = x2 + 2x. What is f(11)?

Student-produced response
Show solution
Answer: 24
Answer Explanation

To get input 11, solve 2x+3=11, so x=4. Then the output is 42+2(4)=24.

Fastest Route

Match the input of f first; do not plug 11 directly into the right side.

Best Tool

Algebra

Why This Route Is Fast

The input-matching step prevents a wrong substitution.

Desmos Note

Not needed.

Common Trap

Using 11 as x instead of as the input to f.

Final Answer

24

Hardtransformed maximumStudent-produced response

5. The maximum point of y=f(x) is (2,9). The function h is defined by h(x)=3f(x+1)−4. What is the maximum y-value of h?

Student-produced response
Show solution
Answer: 23
Answer Explanation

The maximum output of f is 9. The outside transformation changes output values by multiplying by 3 and subtracting 4.

Fastest Route

Compute 3(9)−4=23. The input shift x+1 changes where the maximum occurs, not the maximum y-value.

Best Tool

Mental / Transformation reasoning

Why This Route Is Fast

The question asks for the y-value only, so the horizontal shift can be ignored.

Desmos Note

Not needed.

Common Trap

Trying to change the x-coordinate even though only the maximum y-value is requested.

Final Answer

23

D

Problem-Solving and Data Analysis

Ratios, percentages, data, probability, sampling, and statistical claims.

Ratios, Rates, and Units
Mental ratiosAlgebraUnit cancellation
Overview
This skill tests proportional reasoning, unit rates, scale factors, and unit conversions. The fastest route is usually unit cancellation or a simple ratio model.
SAT Math Strategy Guide
Unit rateFind “per 1” when comparing rates.
ConversionConvert units before setting up the proportion.
Part-to-totalBe clear whether a ratio compares parts or compares a part to the whole.
What the SAT tests
  • ratios
  • proportions
  • unit rates
  • conversions
  • density/speed
  • compound units
  • scale from part-to-total
Practice this skill

These questions build from foundation to SAT-style difficulty. Try each one before revealing the solution.

EasyscaleMultiple choice

1. On a map, 1 inch represents 25 miles. What distance, in miles, is represented by 3.6 inches?

  1. 72
  2. 90
  3. 96
  4. 125
Show solution
Answer: B. 90
Answer Explanation

Multiply the map distance by the scale: 3.6 × 25 = 90 miles.

Fastest Route

Use direct proportion because the scale is linear.

Best Tool

Mental / Algebra

Why This Route Is Fast

The units already match the requested output.

Desmos Note

Not needed.

Common Trap

Dividing by 25 instead of multiplying.

Final Answer

B. 90

Mediumunit rateMultiple choice

2. A machine fills 3/5 of a tank in 18 minutes. At the same constant rate, how many minutes will it take to fill 5/6 of the tank?

  1. 20
  2. 24
  3. 25
  4. 30
Show solution
Answer: C. 25
Answer Explanation

The machine fills 1/30 of a tank per minute, so filling 5/6 takes 25 minutes.

Fastest Route

Find the unit rate: 3/5 ÷ 18 = 1/30. Then 5/6 ÷ 1/30 = 25.

Best Tool

Unit rate

Why This Route Is Fast

The unit rate keeps the proportion organized.

Desmos Note

Not needed.

Common Trap

Multiplying by 18 instead of dividing by the rate.

Final Answer

C. 25

Very Hardcompound unitsStudent-produced response

3. A chemical is added to water at a rate of 2.4 milliliters per liter. How many liters of water can be treated with 3.6 liters of chemical? Use 1 liter = 1,000 milliliters.

Student-produced response
Show solution
Answer: 1500
Answer Explanation

The correct answer is 1500. The chemical amount is 3,600 mL, and each liter of water requires 2.4 mL.

Fastest Route

Convert first: 3.6 L = 3600 mL. Then divide: 3600 ÷ 2.4 = 1500.

Best Tool

Unit cancellation

Why This Route Is Fast

Converting to milliliters first makes the required division direct.

Desmos Note

Not needed.

Common Trap

Using 3.6 instead of 3,600 after the unit conversion.

Final Answer

1500

Percentages and Growth Factors
Multipliers100-student modelsElimination
Overview
Percent questions are about choosing the correct base. The SAT often tests percent change, reverse percent, and consecutive changes.
SAT Math Strategy Guide
MultiplierIncrease by r% means multiply by 1 + r/100. Decrease by r% means multiply by 1 − r/100.
Weighted percentUse a 100-person model when group sizes are percentages.
Base checkAlways identify the original or comparison amount.
What the SAT tests
  • percent increase/decrease
  • reverse percentages
  • discounts
  • growth factors
  • weighted percentages
  • consecutive percent changes
  • percentage points vs percent change
Practice this skill

These questions build from foundation to SAT-style difficulty. Try each one before revealing the solution.

Easypercent decreaseMultiple choice

1. A jacket originally priced at $80 is discounted to $68. What is the percent decrease in the price?

  1. 12%
  2. 15%
  3. 17%
  4. 20%
Show solution
Answer: B. 15%
Answer Explanation

The decrease is $12, and 12/80 = 0.15 = 15%.

Fastest Route

Subtract to find the decrease, then divide by the original price.

Best Tool

Mental / Algebra

Why This Route Is Fast

The original price is the percent-change base.

Desmos Note

Not needed.

Common Trap

Dividing by the discounted price instead of the original price.

Final Answer

B. 15%

Mediumweighted percentageMultiple choice

2. In a school district, 70% of students attend later-start schools and 30% attend earlier-start schools. If 80% of later-start students and 50% of earlier-start students prefer later start times, what percentage of all students should be estimated to prefer later start times?

  1. 65%
  2. 68%
  3. 71%
  4. 80%
Show solution
Answer: C. 71%
Answer Explanation

The groups have different sizes, so use a weighted average: 0.70(80)+0.30(50)=71.

Fastest Route

Use 100 students. Later-start: 70 students, and 80% is 56. Earlier-start: 30 students, and 50% is 15. Total: 71.

Best Tool

100-student model

Why This Route Is Fast

The 100-student model makes the weights visible.

Desmos Note

Not needed.

Common Trap

Averaging 80% and 50% without using the group sizes.

Final Answer

C. 71%

Hardconsecutive percent changesStudent-produced response

3. A store increases the price of an item by p%, then decreases the new price by 25%. The final price is 5% greater than the original price. What is p?

Student-produced response
Show solution
Answer: 40
Answer Explanation

The total multiplier must be 1.05, so 0.75(1+p/100)=1.05.

Fastest Route

Divide by 0.75: 1+p/100=1.40. Therefore p=40.

Best Tool

Multipliers

Why This Route Is Fast

Multipliers avoid percent-change base errors.

Desmos Note

Not needed.

Common Trap

Adding and subtracting percents directly.

Final Answer

40

One-Variable Data: Mean, Median, Range, and Spread
MentalTotalsAvoid exact mean when only direction matters
Overview
One-variable data questions test center and spread. Mean uses total; median uses order; range uses max minus min.
SAT Math Strategy Guide
Meanmean = total ÷ number of values
MedianSort first; the median depends on position.
Rangerange = maximum − minimum
What the SAT tests
  • mean
  • median
  • range
  • IQR/spread intuition
  • effect of outliers
  • adding/removing/replacing values
  • comparing distributions
Practice this skill

These questions build from foundation to SAT-style difficulty. Try each one before revealing the solution.

Mediummean median rangeMultiple choice

1. The data set is 3, 5, 7, 9, 11. If the value 11 is replaced with 19, which statement is true?

  1. The mean and median increase, but the range stays the same.
  2. The mean and range increase, but the median stays the same.
  3. The median and range increase, but the mean stays the same.
  4. The mean, median, and range all increase.
Show solution
Answer: B. The mean and range increase, but the median stays the same.
Answer Explanation

The total increases, so the mean increases. The middle value is still 7, so the median stays the same. The range increases from 8 to 16.

Fastest Route

Compare the old and new lists: 3,5,7,9,11 and 3,5,7,9,19. No exact mean calculation is needed.

Best Tool

Mental

Why This Route Is Fast

Direction of change is enough; exact means would waste time.

Desmos Note

Not needed.

Common Trap

Assuming the median changes because the largest value changed.

Final Answer

B

Mediummean median rangeMultiple choice

2. The data set is 4, 6, 8, 10, 20. If 20 is replaced with 12, which statement is true?

  1. The mean and median decrease, but the range stays the same.
  2. The mean and range decrease, but the median stays the same.
  3. The median and range decrease, but the mean stays the same.
  4. The mean, median, and range all decrease.
Show solution
Answer: B. The mean and range decrease, but the median stays the same.
Answer Explanation

The total decreases, so the mean decreases. The middle value remains 8, so the median stays the same. The range decreases from 16 to 8.

Fastest Route

Compare the old and new ordered lists without calculating exact means.

Best Tool

Mental

Why This Route Is Fast

Direction is enough; exact means are unnecessary.

Desmos Note

Not needed.

Common Trap

Assuming the median changes because the largest value changed.

Final Answer

B. The mean and range decrease, but the median stays the same.

Mediummissing valueStudent-produced response

3. Five numbers have mean 14. Four of the numbers are 8, 11, 15, and 20. What is the fifth number?

Student-produced response
Show solution
Answer: 16
Answer Explanation

The total must be 5 × 14 = 70. The four known numbers sum to 54, so the missing number is 16.

Fastest Route

Use total = mean × count, then subtract the known values.

Best Tool

Mental / Algebra

Why This Route Is Fast

The mean formula gives the total in one step.

Desmos Note

Not needed.

Common Trap

Dividing the known sum by 5 before finding the missing value.

Final Answer

16

Very Hardmean totalStudent-produced response

4. A set of 12 numbers has mean 18. Two numbers, a and b, are added, and the new mean is 21. If a = 2b, what is a?

Student-produced response
Show solution
Answer: 52
Answer Explanation

The correct answer is 52. The original total is 216 and the new total is 294, so the added sum is 78. Since a=2b, a=52.

Fastest Route

Original total: 12(18)=216. New total: 14(21)=294. Added sum: 78. With a=2b, 3b=78, so a=52.

Best Tool

Algebra / Totals

Why This Route Is Fast

Mean problems often become total problems.

Desmos Note

Not needed.

Common Trap

Averaging 18 and 21 or forgetting the count changes from 12 to 14.

Final Answer

52

Two-Variable Data: Tables, Scatterplots, Lines of Best Fit, and Residuals
Mental / Algebra for line equationsDesmos Table for checking values
Overview
Two-variable data questions test trends, predictions, slope/intercept in context, line of best fit, and residuals.
SAT Math Strategy Guide
PredictionSubstitute the given input or output into the model.
Residualresidual = actual − predicted
AssociationA trend or association does not automatically prove causation.
What the SAT tests
  • scatterplot trend
  • line of best fit
  • residual = actual − predicted
  • prediction from model
  • slope/intercept interpretation
  • association vs causation
  • table-to-model reasoning
Practice this skill

These questions build from foundation to SAT-style difficulty. Try each one before revealing the solution.

Mediummodel predictionStudent-produced response

1. A line of best fit relating temperature T to energy use E is E = −1.8T + 246. The model predicts energy use of 156. What temperature does the model predict?

Student-produced response
Show solution
Answer: 50
Answer Explanation

The correct answer is 50. Set E=156 and solve for T.

Fastest Route

Use 156 = −1.8T + 246. Then −90 = −1.8T, so T=50.

Best Tool

Algebra

Why This Route Is Fast

The model is already given, so substitution is direct.

Desmos Note

Not needed.

Common Trap

Substituting 156 for T instead of for E.

Final Answer

50

MediumresidualMultiple choice

2. A model predicts that a plant will be 32 centimeters tall. The actual height is 38 centimeters. What is the residual, in centimeters?

  1. −6
  2. 6
  3. 32
  4. 38
Show solution
Answer: B. 6
Answer Explanation

Residual = actual − predicted = 38 − 32 = 6.

Fastest Route

Use residual = actual − predicted.

Best Tool

Mental

Why This Route Is Fast

Only subtraction is needed once the terms are identified.

Desmos Note

Not needed.

Common Trap

Reversing the subtraction and getting −6.

Final Answer

B. 6

HardresidualMultiple choice

3. A line of best fit predicts that a plant will be 31.2 centimeters tall after 18 days. The plant’s actual height after 18 days is 34.7 centimeters. What is the residual, in centimeters?

  1. −3.5
  2. −2.5
  3. 3.5
  4. 65.9
Show solution
Answer: C. 3.5
Answer Explanation

Choice C is correct. Residual equals actual minus predicted: 34.7−31.2=3.5.

Fastest Route

Use residual = actual − predicted.

Best Tool

Mental / Algebra

Why This Route Is Fast

The formula gives the sign and value in one step.

Desmos Note

Not needed.

Common Trap

Reversing the subtraction and getting −3.5.

Final Answer

C. 3.5

Hardassociation languageMultiple choice

4. A scatterplot shows that students who spend more hours on a practice app tend to have higher quiz scores. Which conclusion is best supported?

  1. Using the app definitely causes every student to score higher.
  2. There is an association between app time and quiz score.
  3. The app lowers quiz scores for students who study less.
  4. Quiz scores determine how many hours students use the app.
Show solution
Answer: B. There is an association between app time and quiz score.
Answer Explanation

A scatterplot can show association, but it does not by itself prove causation.

Fastest Route

Choose the conclusion that matches the evidence without overclaiming.

Best Tool

Conceptual elimination

Why This Route Is Fast

Study-design wording is usually about what can and cannot be concluded.

Desmos Note

Not applicable.

Common Trap

Turning association into causation.

Final Answer

B. There is an association between app time and quiz score.

Probability and Conditional Probability
Restrict denominator firstTable reading
Overview
Probability questions compare favorable outcomes to possible outcomes. Conditional probability means restrict the denominator to the given condition.
SAT Math Strategy Guide
Probabilityfavorable outcomes ÷ possible outcomes
Conditional probabilityRestrict the total to the group named after “given” or implied by the condition.
ComplementP(not A) = 1 − P(A)
What the SAT tests
  • simple probability
  • conditional probability
  • table probability
  • complement probability
  • without-replacement probability
  • inclusion-exclusion
Practice this skill

These questions build from foundation to SAT-style difficulty. Try each one before revealing the solution.

Mediumconditional denominatorStudent-produced response

1. In a group of students, 36 juniors and 24 seniors take calculus. If one calculus student is selected at random, what is the probability that the student is a junior?

Student-produced response
Show solution
Answer: 3/5
Answer Explanation

Since the selected student is known to take calculus, the total is only calculus students: 36+24=60.

Fastest Route

Restrict the denominator first. Probability = 36/60 = 3/5.

Best Tool

Restrict the total

Why This Route Is Fast

Conditional probability becomes easy once the correct denominator is identified.

Desmos Note

Not needed.

Common Trap

Using all students as the denominator instead of only calculus students.

Final Answer

3/5

Hardwithout replacementMultiple choice

2. A bag contains 3 red marbles and 5 blue marbles. If two marbles are selected without replacement, what is the probability that both are red?

  1. 3/64
  2. 3/28
  3. 9/64
  4. 3/8
Show solution
Answer: B. 3/28
Answer Explanation

The probability of red first is 3/8. Then 2 red marbles remain out of 7 total, so multiply: 3/8·2/7=3/28.

Fastest Route

Update the counts after the first selection.

Best Tool

Algebra

Why This Route Is Fast

The without-replacement structure has only two steps.

Desmos Note

Not needed.

Common Trap

Using 3/8 twice as if the first marble were replaced.

Final Answer

B. 3/28

Very Hardconditional probabilityStudent-produced response

3. A table classifies 200 voters by age group and candidate preference. Of 90 voters under 30, 54 prefer Candidate A. Of 110 voters age 30 or older, 44 prefer Candidate A. If a voter who prefers Candidate A is selected at random, what is the probability that the voter is under 30?

Student-produced response
Show solution
Answer: 27/49
Answer Explanation

The correct answer is 27/49. The condition is that the voter prefers Candidate A, so the denominator is 54+44=98.

Fastest Route

Use the restricted denominator: 54/98=27/49.

Best Tool

Restrict the total

Why This Route Is Fast

The condition tells you which row/column becomes the denominator.

Desmos Note

Not needed.

Common Trap

Using 90 or 200 as the denominator.

Final Answer

27/49

Very Hardconditional tableStudent-produced response

4. In a survey, 72 students play an instrument, 45 students play a sport, and 18 students play both. If a student who plays an instrument is selected at random, what is the probability that the student also plays a sport?

Student-produced response
Show solution
Answer: 1/4
Answer Explanation

The condition is that the selected student plays an instrument, so the denominator is 72.

Fastest Route

Use the restricted denominator: 18/72=1/4.

Best Tool

Restrict the total

Why This Route Is Fast

Conditional probability becomes direct once the condition sets the denominator.

Desmos Note

Not needed.

Common Trap

Using all surveyed students or all sport players as the denominator.

Final Answer

1/4

Sampling, Margin of Error, and Inference
Interval reasoningElimination
Overview
Sampling and margin-of-error questions test what conclusions are supported by sample data.
SAT Math Strategy Guide
Margin of errorBuild the interval: estimate − margin to estimate + margin.
MajorityA majority is guaranteed only if the entire interval is above 50%.
OverlapOverlapping intervals do not support a definite “higher” conclusion.
What the SAT tests
  • margin-of-error intervals
  • sample vs population
  • sample statistic vs true population value
  • whether a majority is guaranteed
  • overlapping intervals
  • random sampling and generalization
Practice this skill

These questions build from foundation to SAT-style difficulty. Try each one before revealing the solution.

Mediummargin intervalMultiple choice

1. A random sample of 500 city residents found that 49% support a proposal. The margin of error is ±5 percentage points. Which conclusion is best supported?

  1. A majority definitely supports the proposal.
  2. The true percentage is exactly 49%.
  3. A majority is possible, but not guaranteed.
  4. The margin of error proves support is below 50%.
Show solution
Answer: C. A majority is possible, but not guaranteed.
Answer Explanation

The interval is 44% to 54%, so values above and below 50% are both possible.

Fastest Route

Compute the interval: 49−5=44 and 49+5=54. Since the interval crosses 50, a majority is not guaranteed.

Best Tool

Interval reasoning

Why This Route Is Fast

Margin-of-error questions usually become interval questions.

Desmos Note

Not needed.

Common Trap

Treating 49% as exact or treating 54% as guaranteed.

Final Answer

C

MediumgeneralizationMultiple choice

2. A random sample of 1,000 voters in a state is surveyed about a ballot measure. Which population can the results most reasonably be generalized to?

  1. All voters in the state
  2. All voters in the country
  3. Only the 1,000 surveyed voters
  4. All people in the state, including nonvoters
Show solution
Answer: A. All voters in the state
Answer Explanation

Because the sample was randomly selected from voters in the state, the results can reasonably generalize to that population.

Fastest Route

Identify the population from which the random sample was taken.

Best Tool

Conceptual elimination

Why This Route Is Fast

The population in the sampling frame controls the valid generalization.

Desmos Note

Not applicable.

Common Trap

Generalizing beyond the sampled population.

Final Answer

A. All voters in the state

Very Hardoverlapping intervalsMultiple choice

3. Poll A reports 47% ± 3% support. Poll B reports 53% ± 4% support. Can we conclude that Poll B’s population support is definitely higher than Poll A’s?

  1. Yes, because 53 is greater than 47.
  2. Yes, because both polls have margins of error.
  3. No, because random samples are never useful.
  4. No, because the intervals overlap.
Show solution
Answer: D. No, because the intervals overlap.
Answer Explanation

Choice D is correct. Poll A could be as high as 50%, and Poll B could be as low as 49%, so B is not definitely higher.

Fastest Route

Build the intervals: Poll A is 44% to 50%; Poll B is 49% to 57%. They overlap from 49% to 50%.

Best Tool

Interval reasoning

Why This Route Is Fast

Interval overlap quickly rules out a definite comparison.

Desmos Note

Not needed.

Common Trap

Comparing only the point estimates 47 and 53.

Final Answer

D

Statistical Claims and Study Design
Conceptual elimination
Overview
Study-design questions test observational studies, experiments, random selection, random assignment, association, and causation.
SAT Math Strategy Guide
Random assignmentSupports causal comparison.
Random samplingSupports generalization to the population sampled from.
Observational dataCan show association but usually not causation.
What the SAT tests
  • observational study vs experiment
  • random assignment
  • random sample
  • causation vs association
  • generalization to a population
  • supports vs proves wording
Practice this skill

These questions build from foundation to SAT-style difficulty. Try each one before revealing the solution.

Mediumobservational studyMultiple choice

1. An observational study finds that students who eat breakfast tend to have higher math scores than students who do not. Which conclusion is best supported?

  1. Eating breakfast definitely causes higher math scores.
  2. There is an association between eating breakfast and math scores.
  3. Not eating breakfast prevents learning math.
  4. Breakfast has no relationship to math scores.
Show solution
Answer: B. There is an association between eating breakfast and math scores.
Answer Explanation

An observational study can support association, but it does not prove causation without random assignment or experimental control.

Fastest Route

Choose the conclusion that does not overclaim causation.

Best Tool

Conceptual elimination

Why This Route Is Fast

The study type directly limits the conclusion.

Desmos Note

Not applicable.

Common Trap

Treating an observational relationship as proof of cause and effect.

Final Answer

B. There is an association between eating breakfast and math scores.

Hardrandom assignmentMultiple choice

2. Researchers randomly assigned 150 volunteers to use either Method X or Method Y for four weeks. The Method X group answered an average of 6 more review questions correctly. Which conclusion is best supported?

  1. For these volunteers, Method X caused higher average performance.
  2. Method X will cause every student to answer exactly 6 more correctly.
  3. Method X is proven better for all students.
  4. Method Y prevents students from learning.
Show solution
Answer: A. For these volunteers, Method X caused higher average performance.
Answer Explanation

Random assignment supports cause-and-effect for the volunteers, but volunteers are not automatically representative of all students.

Fastest Route

Look for random assignment and population. Random assignment supports causation for the study participants only.

Best Tool

Conceptual elimination

Why This Route Is Fast

The design feature tells you the strength of the conclusion.

Desmos Note

Not needed.

Common Trap

Confusing random assignment with random sampling.

Final Answer

A

Very Hardsampling plus assignmentMultiple choice

3. A researcher randomly selected 600 students from a district, then randomly assigned them to use either Method A or Method B. Students using Method A scored higher on average. Which conclusion is best supported?

  1. Method A caused every student to score higher.
  2. The result cannot be generalized at all.
  3. Only association is supported, not causation.
  4. Method A caused higher average scores for the sample, and the result may generalize to the district.
Show solution
Answer: D. Method A caused higher average scores for students in the sample, and the result may be generalized to the district.
Answer Explanation

Choice D is correct. Random selection supports generalization to the district, and random assignment supports causal comparison.

Fastest Route

Identify both design features: random selection plus random assignment.

Best Tool

Conceptual elimination

Why This Route Is Fast

Both features together allow a stronger conclusion than either one alone.

Desmos Note

Not needed.

Common Trap

Saying the result applies to every student or guarantees individual improvement.

Final Answer

D

Very Hardobservational claimMultiple choice

4. A city collects data and finds that neighborhoods with more bike lanes tend to have lower car-accident rates. The data were observational and did not involve random assignment. Which conclusion is best supported?

  1. Adding bike lanes definitely causes every neighborhood to have fewer accidents.
  2. There is an association between bike-lane availability and car-accident rates.
  3. Bike lanes have no relationship to accident rates.
  4. Car accidents cause cities to remove bike lanes.
Show solution
Answer: B. There is an association between bike-lane availability and car-accident rates.
Answer Explanation

Observational data can support an association, but it does not by itself prove cause and effect.

Fastest Route

Identify the study type. Without random assignment, avoid causal wording.

Best Tool

Conceptual elimination

Why This Route Is Fast

Study-design questions often depend on whether the conclusion overclaims causation.

Desmos Note

Not applicable.

Common Trap

Turning an observed relationship into a definite causal claim.

Final Answer

B

G

Geometry and Trigonometry

Area, volume, triangles, similarity, trigonometry, circles, and coordinate geometry.

Area, Perimeter, Volume, and Scale
Use ChoicesAlgebraFormula recognition
Overview
This skill tests formulas, units, scale factors, and algebraic dimensions.
SAT Math Strategy Guide
Scale factorsLength scales by k, area by k2, and volume by k3.
VolumeRectangular prism volume = length × width × height.
ChoicesWhen choices are small, simplify first and test.
What the SAT tests
  • area
  • perimeter
  • volume
  • surface area
  • algebraic dimensions
  • scale factors
  • length vs area vs volume units
Practice this skill

These questions build from foundation to SAT-style difficulty. Try each one before revealing the solution.

Basicrectangle areaMultiple choice

1. A rectangle has length 12 and width 7. What is its area?

  1. 19
  2. 38
  3. 84
  4. 144
Show solution
Answer: C. 84
Answer Explanation

Area of a rectangle is length × width, so 12 × 7 = 84.

Fastest Route

Multiply length by width.

Best Tool

Mental

Why This Route Is Fast

This is a one-step formula question.

Desmos Note

Not needed.

Common Trap

Finding perimeter instead of area.

Final Answer

C. 84

Mediumarea scaleMultiple choice

2. Two similar triangles have corresponding side lengths in a ratio of 3:5. If the area of the larger triangle is 100, what is the area of the smaller triangle?

  1. 36
  2. 45
  3. 60
  4. 64
Show solution
Answer: A. 36
Answer Explanation

Choice A is correct. The area ratio is the square of the side ratio, so smaller-to-larger area is 9:25.

Fastest Route

Compute 100 · 9/25 = 36.

Best Tool

Geometry theorem

Why This Route Is Fast

Squaring the scale factor gives the area relationship immediately.

Desmos Note

Not needed.

Common Trap

Using the side ratio 3:5 directly for area.

Final Answer

A. 36

Mediumscale factorStudent-produced response

3. Two similar solids have side lengths in a ratio of 2:5. If the smaller solid has volume 24, what is the volume of the larger solid?

Student-produced response
Show solution
Answer: 375
Answer Explanation

The volume scale factor is (5/2)3 = 125/8. The larger volume is 24·125/8=375.

Fastest Route

Cube the side-length scale factor before scaling volume.

Best Tool

Algebra

Why This Route Is Fast

Volume uses cubic scaling, not linear scaling.

Desmos Note

Not needed.

Common Trap

Multiplying by 5/2 instead of cubing the factor.

Final Answer

375

Hardrectangular prismMultiple choice

4. A rectangular prism has volume 1,080. Its length is 10, its width is 2x, and its height is x + 3. What is the positive value of x?

  1. 4
  2. 5
  3. 6
  4. 9
Show solution
Answer: C. 6
Answer Explanation

The equation is 1080=10(2x)(x+3), which simplifies to 54=x(x+3). Testing x=6 gives 6(9)=54.

Fastest Route

Simplify first, then test the choices.

Best Tool

Use Choices or Algebra

Why This Route Is Fast

Testing small choices after simplification is faster than factoring a quadratic.

Desmos Note

Not needed.

Common Trap

Forgetting that the width is 2x, not x.

Final Answer

C. 6

Lines, Angles, and Triangles
Mental theorem recognitionAlgebra
Overview
Triangle questions test angles, sides, area, right triangles, and theorem recognition.
SAT Math Strategy Guide
Triangle sumInterior angles of a triangle add to 180°.
Exterior angleAn exterior angle equals the sum of the two remote interior angles.
Right-triangle altitudeIf altitude from the right angle hits the hypotenuse at D, then leg² = adjacent hypotenuse segment × full hypotenuse.
What the SAT tests
  • triangle angle sum
  • exterior angles
  • right triangles
  • Pythagorean theorem
  • special right triangles
  • altitude to hypotenuse theorem
  • algebraic side/angle expressions
Practice this skill

These questions build from foundation to SAT-style difficulty. Try each one before revealing the solution.

Easyangle sumStudent-produced response

1. Two angles of a triangle measure 47° and 68°. What is the measure, in degrees, of the third angle?

Student-produced response
Show solution
Answer: 65
Answer Explanation

The angles in a triangle sum to 180°, so the third angle is 180 − 47 − 68 = 65.

Fastest Route

Subtract the two known angles from 180.

Best Tool

Mental

Why This Route Is Fast

This is a direct triangle-sum question.

Desmos Note

Not needed.

Common Trap

Forgetting to subtract both angles.

Final Answer

65

Mediumexterior angleMultiple choice

2. In a triangle, two interior angles measure 48° and 67°. What is the measure of the exterior angle adjacent to the third interior angle?

  1. 65°
  2. 77°
  3. 105°
  4. 115°
Show solution
Answer: D. 115°
Answer Explanation

Choice D is correct. The exterior angle equals the sum of the two remote interior angles: 48+67=115.

Fastest Route

Use the exterior angle theorem instead of finding the third angle first.

Best Tool

Mental theorem

Why This Route Is Fast

The theorem gives the exterior angle in one addition.

Desmos Note

Not needed.

Common Trap

Giving the third interior angle, 65°, instead of the exterior angle.

Final Answer

D. 115°

Mediumspecial right triangleMultiple choice

3. In a 30°-60°-90° triangle, the shortest side has length 6. What is the length of the hypotenuse?

  1. 62
  2. 63
  3. 12
  4. 18
Show solution
Answer: C. 12
Answer Explanation

In a 30°-60°-90° triangle, the sides are in the ratio 1 : √3 : 2. The hypotenuse is twice the shortest side, so it is 12.

Fastest Route

Use the special-right-triangle ratio.

Best Tool

Mental

Why This Route Is Fast

The ratio avoids the Pythagorean theorem.

Desmos Note

Not needed.

Common Trap

Multiplying by √3 instead of 2.

Final Answer

C. 12

Hardaltitude theoremMultiple choice

4. In right triangle ABC, angle C = 90°. The altitude from C to hypotenuse AB meets AB at D. If AD = 5 and DB = 20, what is AC?

  1. 5
  2. 55
  3. 105
  4. 25
Show solution
Answer: B. 55
Answer Explanation

The full hypotenuse is 25. The theorem gives AC2 = AD · AB = 5·25=125, so AC=55.

Fastest Route

Use the altitude-to-hypotenuse theorem: leg² = adjacent hypotenuse segment × whole hypotenuse.

Best Tool

Geometry theorem

Why This Route Is Fast

Recognizing the theorem avoids reconstructing the whole triangle.

Desmos Note

Not needed.

Common Trap

Using DB instead of AD for side AC.

Final Answer

B. 55

Hardaltitude to hypotenuseMultiple choice

5. In right triangle ABC, angle C = 90°. The altitude from C to hypotenuse AB meets AB at D. If AD=9 and DB=16, what is AC?

  1. 12
  2. 15
  3. 20
  4. 25
Show solution
Answer: B. 15
Answer Explanation

The full hypotenuse is AB=25. The altitude theorem gives AC2 = AD·AB = 9·25 = 225, so AC=15.

Fastest Route

Recognize the right-triangle altitude theorem.

Best Tool

Geometry theorem

Why This Route Is Fast

The theorem avoids reconstructing the whole triangle.

Desmos Note

Not useful.

Common Trap

Using DB instead of AD for side AC.

Final Answer

B. 15

Similarity and Right Triangle Trigonometry
Ratio scalingMentalAlgebra
Overview
This skill covers proportional figures, scale factors, sine, cosine, tangent, and right-triangle ratios.
SAT Math Strategy Guide
SOH-CAH-TOAsin = opposite/hypotenuse, cos = adjacent/hypotenuse, tan = opposite/adjacent.
Special triplesRecognize 3-4-5, 5-12-13, 8-15-17.
ScaleScale all corresponding sides by the same factor.
What the SAT tests
  • similar triangles
  • side ratios
  • area scale factor
  • volume scale factor
  • sine/cosine/tangent
  • complementary trig
  • Pythagorean triples
Practice this skill

These questions build from foundation to SAT-style difficulty. Try each one before revealing the solution.

Mediumtriangle similarityStudent-produced response

1. Triangle A is similar to Triangle B. A side of Triangle A has length 18, and the corresponding side of Triangle B has length 30. If another side of Triangle A has length 24, what is the corresponding side length in Triangle B?

Student-produced response
Show solution
Answer: 40
Answer Explanation

The scale factor from Triangle A to Triangle B is 30/18 = 5/3.

Fastest Route

Multiply the corresponding side by the scale factor: 24 · 5/3 = 40.

Best Tool

Ratio scaling

Why This Route Is Fast

Similar figures use the same scale factor for all corresponding side lengths.

Desmos Note

Not needed.

Common Trap

Using an area or volume scale factor instead of a side-length scale factor.

Final Answer

40

Mediumarea scale factorMultiple choice

2. Two similar triangles have corresponding side lengths in a ratio of 4:7. If the area of the smaller triangle is 48, what is the area of the larger triangle?

  1. 84
  2. 112
  3. 147
  4. 196
Show solution
Answer: C. 147
Answer Explanation

The side-length scale factor from smaller to larger is 7/4, so the area scale factor is 49/16.

Fastest Route

Compute 48 · 49/16 = 3 · 49 = 147.

Best Tool

Algebra / Scaling

Why This Route Is Fast

Area scales by the square of the side-length scale factor.

Desmos Note

Not needed.

Common Trap

Multiplying by 7/4 instead of squaring the scale factor.

Final Answer

C. 147

Mediumcomplementary trigStudent-produced response

3. Angles A and B are complementary acute angles in a right triangle. If sin A = 5/13, what is cos B?

Student-produced response
Show solution
Answer: 5/13
Answer Explanation

For complementary acute angles in a right triangle, sin A = cos B. Therefore cos B = 5/13.

Fastest Route

Use the complementary-angle identity.

Best Tool

Mental

Why This Route Is Fast

No side lengths need to be calculated.

Desmos Note

Not needed.

Common Trap

Treating sin A and cos B as unrelated values.

Final Answer

5/13

Very Hardtrig ratioStudent-produced response

4. In a right triangle, sin A = 5/13 and the hypotenuse is 39. What is the area of the triangle?

Student-produced response
Show solution
Answer: 270
Answer Explanation

The ratio is a 5-12-13 triangle scaled by 3, so the legs are 15 and 36.

Fastest Route

Since the hypotenuse 13 scales to 39, the scale factor is 3. Area = 1/2(15)(36)=270.

Best Tool

Mental / Ratio scaling

Why This Route Is Fast

Recognizing the Pythagorean triple avoids solving for the missing leg from scratch.

Desmos Note

Not needed.

Common Trap

Using 5 and 13 as actual side lengths instead of ratio parts.

Final Answer

270

Very Hardtrig areaStudent-produced response

5. In a right triangle, sin A = 3/5, and the hypotenuse is 40. What is the area of the triangle?

Student-produced response
Show solution
Answer: 384
Answer Explanation

The triangle is a 3-4-5 triangle scaled by 8, so the legs are 24 and 32.

Fastest Route

Recognize the 3-4-5 triple. Area = 1/2(24)(32)=384.

Best Tool

Mental / Algebra

Why This Route Is Fast

The Pythagorean triple avoids solving for the missing leg from scratch.

Desmos Note

Not needed.

Common Trap

Using 40 as a leg instead of the hypotenuse.

Final Answer

384

Circles: Arcs, Sectors, Equations, Chords, and Tangents
AlgebraDesmos Graph for visual checkExact route for symbolic answers
Overview
Circle questions test radius/diameter, circumference, area, arcs, sectors, circle equations, chords, and tangents. High-score items often combine coordinate geometry and a theorem.
SAT Math Strategy Guide
Sector shortcutFor sector area A, radius r, and arc length s: A = 1/2rs.
Chord from lineSubstitute the line into the circle equation.
TangentDistance from center to tangent line equals radius.
What the SAT tests
  • radius vs diameter
  • circumference and area
  • arc length
  • sector area
  • circle equation
  • chord length from a line
  • completing the square
  • tangent-radius perpendicular relationship
  • distance from center to tangent line
Practice this skill

These questions build from foundation to SAT-style difficulty. Try each one before revealing the solution.

Hardsector areaStudent-produced response

1. A sector of a circle has arc length 8π and area 40π. What is the radius of the circle?

Student-produced response
Show solution
Answer: 10
Answer Explanation

Use A = 1/2rs.

Fastest Route

Substitute: 40π = 1/2(r)(8π)=4πr, so r=10.

Best Tool

Formula shortcut

Why This Route Is Fast

The sector shortcut avoids central-angle formulas.

Desmos Note

Not needed.

Common Trap

Using full-circle area and circumference formulas separately.

Final Answer

10

Hardsector shortcutStudent-produced response

2. A sector of a circle has arc length 15π and area 60π. What is the radius of the circle?

Student-produced response
Show solution
Answer: 8
Answer Explanation

Use A=1/2rs. Then 60π = 1/2(r)(15π) = 7.5πr, so r=8.

Fastest Route

Use the sector area shortcut with arc length.

Best Tool

Formula recognition

Why This Route Is Fast

The shortcut avoids central-angle formulas.

Desmos Note

Not needed.

Common Trap

Using full-circle formulas separately.

Final Answer

8

Very Hardcircle chordMultiple choice

3. The line y = 0 intersects the circle x2 + y2 − 4x + 6y − 5 = 0 at two points. What is the distance between those two points?

  1. 4
  2. 5
  3. 6
  4. 10
Show solution
Answer: C. 6
Answer Explanation

Setting y=0 gives x2−4x−5=0, with roots −1 and 5. The distance is 6.

Fastest Route

Substitute y=0 immediately, solve for the two x-values, and subtract them.

Best Tool

Algebra

Why This Route Is Fast

There is no need to complete the square for the whole circle when the chord lies on y=0.

Desmos Note

Not needed.

Common Trap

Finding the radius instead of the chord length.

Final Answer

C. 6

Very Hardtangent lineMultiple choice

4. In the xy-plane, the line y = x + c is tangent to the circle x2 + y2 = 18. What is the positive value of c?

  1. 3
  2. 32
  3. 6
  4. 62
Show solution
Answer: C. 6
Answer Explanation

The radius is 18=32. The distance from (0,0) to x−y+c=0 is |c|/√2, so c=6.

Fastest Route

Set distance from center to line equal to radius: |c|/√2 = 32.

Best Tool

Distance from point to line

Why This Route Is Fast

Tangency means the distance from the center to the tangent line equals the radius.

Desmos Note

Not needed.

Common Trap

Using 18 as the radius instead of √18.

Final Answer

C. 6

Very Hardcircle chordMultiple choice

5. The line y=0 intersects the circle x2 + y2 − 8x + 2y − 5 = 0 at two points. What is the distance between those two points?

  1. 25
  2. 221
  3. 45
  4. 62
Show solution
Answer: B. 221
Answer Explanation

Set y=0 to get x2 − 8x − 5 = 0. The roots are 4 ± 21, so the distance between them is 221.

Fastest Route

Substitute y = 0 immediately instead of completing the square for the whole circle.

Best Tool

Algebra

Why This Route Is Fast

The line gives a one-variable quadratic right away.

Desmos Note

Graphing can verify the chord, but algebra is cleaner for the exact answer.

Common Trap

Giving the radius instead of the chord length.

Final Answer

B. 221

Coordinate Geometry
Mental right-triangle structureAlgebra
Overview
Coordinate geometry combines slope, midpoint, distance, line equations, and circle equations.
SAT Math Strategy Guide
MidpointAverage the x-values and average the y-values.
DistanceUse right-triangle legs before writing the full distance formula.
Perpendicular slopesSlopes multiply to −1.
What the SAT tests
  • midpoint
  • distance
  • slope
  • coordinate signs
  • perpendicular/parallel slopes
  • unknown coordinate from distance
  • geometric facts on the coordinate plane
Practice this skill

These questions build from foundation to SAT-style difficulty. Try each one before revealing the solution.

EasymidpointMultiple choice

1. What is the midpoint of the segment with endpoints (−2,5) and (8,1)?

  1. (3,3)
  2. (5,4)
  3. (6,−4)
  4. (10,6)
Show solution
Answer: A. (3,3)
Answer Explanation

Average the x-coordinates and y-coordinates: (−2+8)/2=3 and (5+1)/2=3.

Fastest Route

Average the coordinates component by component.

Best Tool

Mental

Why This Route Is Fast

The numbers are small and direct.

Desmos Note

Not needed.

Common Trap

Adding coordinates without dividing by 2.

Final Answer

A. (3,3)

MediummidpointStudent-produced response

2. The midpoint of (a, 4) and (2, 10) is (5, 7). What is a?

Student-produced response
Show solution
Answer: 8
Answer Explanation

The correct answer is 8. The x-coordinate of the midpoint is the average of a and 2.

Fastest Route

Set (a+2)/2 = 5. Then a+2=10 and a=8.

Best Tool

Algebra

Why This Route Is Fast

The y-coordinates already confirm the midpoint, so only the x-coordinate matters.

Desmos Note

Not needed.

Common Trap

Averaging all four coordinates together.

Final Answer

8

MediumdistanceStudent-produced response

3. What is the distance between (−1,4) and (7,−2)?

Student-produced response
Show solution
Answer: 10
Answer Explanation

The horizontal difference is 8 and the vertical difference is 6. The distance is the hypotenuse of a 6-8-10 right triangle, so it is 10.

Fastest Route

Use the right-triangle structure instead of writing the full formula.

Best Tool

Mental / Geometry

Why This Route Is Fast

Recognizing the 6-8-10 triple saves calculation.

Desmos Note

Not needed.

Common Trap

Forgetting to square both coordinate differences if using the formula.

Final Answer

10

Very Harddistance structureStudent-produced response

4. Point P(a, 4) is 13 units from Q(−5, −1). If a > −5, what is a?

Student-produced response
Show solution
Answer: 7
Answer Explanation

The correct answer is 7. The vertical difference is 5, and the distance is 13, so the horizontal difference must be 12.

Fastest Route

Use the 5-12-13 right triangle. Since a is greater than −5, a = −5 + 12 = 7.

Best Tool

Mental / Distance

Why This Route Is Fast

Recognizing the Pythagorean triple avoids the full distance formula.

Desmos Note

Not needed.

Common Trap

Using the other possible x-coordinate, −17, even though a > −5.

Final Answer

7

Very Hardcircle distanceStudent-produced response

5. Point R(3,b) is on a circle centered at (−1,2) with radius 5. If b > 2, what is b?

Student-produced response
Show solution
Answer: 5
Answer Explanation

The horizontal distance from (−1,2) to (3,b) is 4. The radius is 5, so the vertical distance must be 3.

Fastest Route

Use the 3-4-5 right triangle. Since b > 2, use b=2+3=5.

Best Tool

Geometry / Distance

Why This Route Is Fast

Recognizing the right-triangle structure avoids the full distance formula.

Desmos Note

Not needed.

Common Trap

Using b=−1, the lower point on the circle, despite the condition b > 2.

Final Answer

5

C

Calculator Strategy: Desmos, Tables, Graphs.

Strategy section · not an official SAT Math domain
Desmos Graphing: Intersections, Zeros, and Extrema
Desmos GraphRoute selection
Overview
Use Desmos when a question asks for intersections, zeros, approximate solutions, rounded answers, or maximum/minimum points. This is an overlay strategy, not a scored SAT Math domain.
SAT Math Strategy Guide
Best useIntersections, zeros, rounded solutions, and extrema.
Coordinate warningRead x if the question asks for x; read y only if it asks for a value/output.
RestrictionUse domain restrictions such as x > 0 when the problem gives them.
What the SAT tests
  • graph two sides separately
  • tap intersections
  • read the requested coordinate
  • graph distance squared instead of distance when minimizing
  • use restrictions like x > 0 when needed
Practice this skill

These questions build from foundation to SAT-style difficulty. Try each one before revealing the solution.

Lesson Checkapproximate rootLesson Check

1. The equation 0.45x² + 1.8x = 11.7 has a positive solution. Which value is closest to that solution?

  1. 2.8
  2. 3.5
  3. 4.2
  4. 5.1
Show solution
Answer: 3.5
Answer Explanation

The positive solution is about 3.48, so 3.5 is closest.

Fastest Route

Graph y=0.45x2+1.8x and y=11.7, or table-check the choices.

Best Tool

Desmos Graph

Why This Route Is Fast

The equation has decimals and asks for a closest value, so approximation is efficient.

Desmos Note

Graph both sides separately and tap the positive intersection.

Common Trap

Rounding before reading the intersection carefully.

Final Answer

3.5

Lesson Checkrounded zeroLesson Check

2. The equation x² − 7.4x + 10 = 0 has two solutions. What is the greater solution, rounded to the nearest tenth?

Lesson check / route practice
Show solution
Answer: 5.6
Answer Explanation

The greater zero is about 5.62, so the rounded answer is 5.6.

Fastest Route

Graph y=x2−7.4x+10 and y=0. Read the greater x-intercept.

Best Tool

Desmos Graph

Why This Route Is Fast

Graphing is faster because the answer is rounded.

Desmos Note

Use the x-intercepts; choose the greater x-value.

Common Trap

Reading the smaller zero or reading the y-coordinate.

Final Answer

5.6

Desmos Tables and Function Values
Desmos TableAlgebra
Overview
Use tables when checking function values, matching equations to a table, comparing two expressions at specific inputs, or testing choices.
SAT Math Strategy Guide
Table useCreate a table when inputs are specific or choices are easy to test.
Function entryUse parentheses around grouped numerators and denominators.
Read carefullyA table can show many columns; answer only what is asked.
What the SAT tests
  • evaluating h(7)
  • matching tables to equations
  • testing answer choices
  • checking a parameter at one input
  • reading the requested value carefully
Practice this skill

These questions build from foundation to SAT-style difficulty. Try each one before revealing the solution.

Lesson Checkfunction valueLesson Check

1. Let h(x) = ((x − 2)2 + 5)/(x + 3). What is h(7)?

Lesson check / route practice
Show solution
Answer: 3
Answer Explanation

The correct answer is 3. At x=7, the numerator is (5)2+5=30 and the denominator is 10.

Fastest Route

Use a Desmos table or substitute directly: 30/10=3.

Best Tool

Desmos Table or Algebra

Why This Route Is Fast

The input is specific, so a table gives the value immediately.

Desmos Note

Enter h(x)=((x-2)^2+5)/(x+3), then add a table and read x=7.

Common Trap

Entering (x−2)2 + 5/x + 3 without grouping the fraction.

Final Answer

3

Lesson Checkcompare functionsLesson Check

2. At x=4, how much greater is p(x)=2x2−1 than q(x)=x+23?

Lesson check / route practice
Show solution
Answer: 4
Answer Explanation

The correct answer is 4. p(4)=31 and q(4)=27, so the difference is 4.

Fastest Route

Use a table with both functions at x=4, then subtract 31−27.

Best Tool

Desmos Table

Why This Route Is Fast

Tables are efficient when comparing function values at a named input.

Desmos Note

Make a table for p(x) and q(x), then compare the row x=4.

Common Trap

Subtracting in the wrong order and getting −4.

Final Answer

4

Answer-Choice Strategy: Backsolving and Elimination
Use ChoicesEliminateBacksolve
Overview
Use choices when numbers are simple, when choices are ordered, or when direct algebra is slower than checking.
SAT Math Strategy Guide
Use choicesWhen choices are small, plug them into the simplified condition.
EliminateUse bounds, units, and reasonableness before calculating.
Backsolve warningCheck the original question, not an equation you accidentally changed.
What the SAT tests
  • test simple numeric choices
  • use middle choices when ordered
  • eliminate impossible values
  • use bounds
  • check original condition, not a distorted version
Practice this skill

These questions build from foundation to SAT-style difficulty. Try each one before revealing the solution.

Lesson CheckeliminationLesson Check

1. A weighted average is based on 70% of a group with value 80 and 30% with value 50. Before calculating exactly, which range must the answer be in?

Lesson check / route practice
Show solution
Answer: Between 50 and 80, closer to 80
Answer Explanation

The answer must be between the two group values and closer to 80 because the 80 group is larger.

Fastest Route

Eliminate choices outside 50 to 80 and choices closer to 50. Then compute if needed: 0.70(80)+0.30(50)=71.

Best Tool

Eliminate, then Mental

Why This Route Is Fast

Reasonableness can remove bad answers before arithmetic.

Desmos Note

Not needed.

Common Trap

Averaging 80 and 50 without using weights.

Final Answer

Between 50 and 80, closer to 80

Lesson Checkuse choicesLesson Check

2. For 48 = x(x + 2), the answer choices are 4, 5, 6, and 8. Which choice works?

  1. 4
  2. 5
  3. 6
  4. 8
Show solution
Answer: 6
Answer Explanation

The correct answer is 6 because 6(8)=48.

Fastest Route

Test the choices in the simplified equation.

Best Tool

Use Choices

Why This Route Is Fast

Small integer choices make direct testing faster than factoring.

Desmos Note

Not needed.

Common Trap

Testing in an unsimplified equation and making arithmetic harder.

Final Answer

6

Calculator Entry Accuracy and When Not to Use Desmos
Calculator accuracyMentalAlgebra
Overview
Calculator errors usually come from missing parentheses, negative numbers, exponents, or entering a different expression from the problem. High scorers choose the fastest route, not the fanciest one.
SAT Math Strategy Guide
ParenthesesType grouped fractions as ((numerator))/(denominator).
Negative numbersUse parentheses for negative inputs, such as (-3)2.
Do not overuseSkip Desmos when the structure is obvious mentally.
What the SAT tests
  • fractions need grouped numerator and denominator
  • negative inputs need parentheses
  • binomials need parentheses before squaring
  • read x vs y from graph
  • skip Desmos when algebra is simpler
Practice this skill

These questions build from foundation to SAT-style difficulty. Try each one before revealing the solution.

Lesson Checkentry accuracyLesson Check

1. Which Desmos entry correctly represents (x + 5)/(x − 2)?

  1. x+5/x-2
  2. (x+5)/(x-2)
  3. x+(5/x)-2
  4. (x+5)/x-2
Show solution
Answer: B. (x+5)/(x−2)
Answer Explanation

Choice B is correct because it groups the full numerator and the full denominator.

Fastest Route

Use parentheses around both groups: (x+5)/(x−2).

Best Tool

Calculator accuracy

Why This Route Is Fast

Grouping prevents Desmos from dividing only part of the expression.

Desmos Note

The second entry is correct.

Common Trap

Typing x+5/x−2, which means x + 5/x − 2, not the intended fraction.

Final Answer

B. (x+5)/(x−2)

Lesson Checkwhen not to use DesmosLesson Check

2. If 5x + 7 = 32, what is the fastest route to find 10x + 14?

Lesson check / route practice
Show solution
Answer: Mental: double 32
Answer Explanation

The fastest route is mental because 10x+14 = 2(5x+7).

Fastest Route

Double the given value: 2(32)=64.

Best Tool

Mental

Why This Route Is Fast

The expression target is obvious, so graphing or solving for x is unnecessary.

Desmos Note

Not worth it.

Common Trap

Opening Desmos for a one-step structure question.

Final Answer

64

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