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

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.**2.26A 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

D.

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

divide both sides by 6 to simplify

5 feet

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

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

the perimeter is

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

Do the math: