If a pencil's length and diameter are both multiplied by 10, then its volume is multiplied by
A)10.
B)100.
C)1000.
D)10,000.
E)none of the above

Question

Quizplus · Accepted Answer

The volume of a cylinder (like a pencil) is calculated as πr^2h. If both the diameter (and thus the radius) and the height are multiplied by 10, the new volume is π(10r)^2(10h) = 100πr^2 * 10h = 1000πr^2h, which is 1000 times the original volume.

If a Pencil's Length and Diameter Are Both Multiplied by 10