GED Math Practice Questions: Volume and Surface Area - dummies

GED Math Practice Questions: Volume and Surface Area

The GED Mathematical Reasoning test is likely to ask a few questions that involve volume and surface area. When taking the computer version of the test, a formula sheet is supplied, but you will have to know how to apply these formulas.

The following sample questions ask you to find the diameter of a can based on its volume and height, and the slant length of a pyramid, given its side length and surface area.

Practice questions

  1. If a can is designed to contain 24 cubic inches of coconut water and has to be 6 inches tall to fit on the shelves in a store, what would be its diameter in inches?

    A. 1.72

    B. 1.27

    C. 1.79

    D. 2.26

  2. A pyramid has a square base with one of its sides being 3 feet long and a total surface area of 39 square feet. What is the slant length of one of its sides?

Answers and explanations

  1. D.

    The can would be 2.26 inches in diameter. Substituting in the formula for the volume of a right cylinder

    Formula for the volume of a right cylinder.

    divide both sides by 6 to simplify

    four equals Pi multiplied by the square radius, or the square radius equals four divided by pi.

  2. 5 feet

    To answer this question, use the surface area formula for a pyramid,

    The surface area formula for a pyramid

    and plug in the values you have: The area of the base is

    three times three equals nine.

    the perimeter is

    three times four equals twelve.

    and the surface area is 39 square feet, so you have

    Replace the values you know in the surface area formula for a pyramid.

    Do the math:

    do the math to find the value of s.