Volume and Surface Area · Sub-skill drill

Composite Solids

A composite solid is built from two or more standard solids — a cylinder topped by a hemisphere, a cone on top of a cylinder, a box with a triangular prism removed. The volume of a composite is the sum or difference of the volumes of the parts. The skill is identifying the parts cleanly and choosing whether to add or subtract. The College Board reuses a small set of composite shapes; recognizing them by sketch is faster than re-deriving each time.

How this sub-skill is tested on the SAT

A composite solid is built from two or more standard solids — a cylinder topped by a hemisphere, a cone on top of a cylinder, a box with a triangular prism removed. The volume of a composite is the sum or difference of the volumes of the parts. The skill is identifying the parts cleanly and choosing whether to add or subtract. The College Board reuses a small set of composite shapes; recognizing them by sketch is faster than re-deriving each time.

This sub-skill sits inside the broader Volume and Surface Area topic, which is part of the College Board's Additional Topics in Math content domain. Additional Topics in Math is the smallest official SAT Math domain by raw question count, but it carries outsized weight because the questions are concentrated at the harder end of each section. You will see roughly six of these per test, and they tend to separate students aiming for a 750 from students aiming for an 800. The domain covers right triangle trigonometry, circle theorems, volume formulas, complex number arithmetic, and the geometry of lines in the coordinate plane. Most of the formulas you need are listed at the start of the math section — but the test rewards students who have

Practice questions in this drill set

Below are 6 practice questions targeting this exact sub-skill, ordered from easier to harder. Each question is tagged with its target score band so you can focus on questions that match the band you are working out of. Worked solutions are open by default — read each one even if you got the question right, because the way the solution is structured often reveals a faster path than the one you used.

  1. 400-500 easy

    What is the volume of a rectangular box with length 5, width 6, and height 3?

    1. A 126
    2. B 91
    3. C 90
    4. D 14
    Worked solution

    Answer: C — 90

    Volume of a rectangular prism is V = lwh = 5 × 6 × 3 = 90.

  2. 500-600 easy

    A cylinder has radius 4 and height 6. What is its volume? Use π ≈ 3.14.

    1. A 301.59
    2. B 150.80
    3. C 24.00
    4. D 50.27
    Worked solution

    Answer: A — 301.59

    Volume of a cylinder is V = πr^2h = π(4)^2(6) = 301.59.

  3. 500-600 medium

    A sphere has radius 3. What is its volume? Use π ≈ 3.14.

    1. A 18.85
    2. B 84.82
    3. C 113.10
    4. D 114.1
    Worked solution

    Answer: C — 113.10

    Volume of a sphere is V = (4/3)πr^3 = (4/3)π(3)^3 = 113.10.

  4. 600-700 medium

    What is the volume of a rectangular box with length 10, width 6, and height 8?

    1. A 376
    2. B 24
    3. C 480
    4. D 481
    Worked solution

    Answer: C — 480

    Volume of a rectangular prism is V = lwh = 10 × 6 × 8 = 480.

  5. 700-800 hard

    A cylinder has radius 3 and height 3. What is its volume? Use π ≈ 3.14.

    1. A 84.82
    2. B 28.27
    3. C 56.55
    4. D 9.00
    Worked solution

    Answer: A — 84.82

    Volume of a cylinder is V = πr^2h = π(3)^2(3) = 84.82.

  6. 700-800 hard

    A sphere has radius 6. What is its volume? Use π ≈ 3.14.

    1. A 904.78
    2. B 452.39
    3. C 678.58
    4. D 37.70
    Worked solution

    Answer: A — 904.78

    Volume of a sphere is V = (4/3)πr^3 = (4/3)π(6)^3 = 904.78.

Why this band assignment matters

Every question in this drill is tagged with a target score band — 400–500, 500–600, 600–700, or 700–800 — based on its difficulty and the patterns the College Board uses for questions at each level. If you are aiming to break out of a 580 plateau, the 600–700 questions in this drill are your highest-leverage practice. If you are chasing 750+, the 700–800 questions here are the ones that separate the top 10% of test takers from everyone else.

Use the band tags to filter your work. If you can confidently solve every 400–500 and 500–600 question without notes, move to the 600–700 set. If those land cleanly, the 700–800 set is your final boss. The worked solutions in this drill are written so that even the hardest questions become learnable patterns once you have seen the structure of the solve a few times.