Question

A cylinder’s radius is reduced to 2/5 its original size and the height is quadrupled. How has the volume of the cylinder changed?

Answer 1

The volume of the cylinder:
V = r² π h
A radius is reduced to 2/5 its original size and the height is quadrupled.
V ( new ) = ( 2/5 r )² π · 4 h = 4/25 r² π · 4 h = 16/25 r² π h = 16/25 V
Answer:
The new volume has 16/25 the volume of the original cylinder.