Question

A student said the volume of a cylinder with a 7-inch diameter is two times the volume of a cylinder with

the same height and a 3.5-inch radius. What is the error?

Answer 1

The volume of the first is not 2 * volume of the second. They both have the same volume.

Explanation:

The 2 cylinders described are identical. The diameter = 2 times the radius, so the radius of the first cylinder = 1/2 * 7 = 3.5 in, which is the same as the radius of the second one. Also the heights are the same so the volumes are the same too.

Answer 2

When you find the volume of the cylinder you square instead which isn't equal to multiplying so the answer will be more then doubled.

Explanation: