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?
A. 8/25
B. 16/25
C. 64/25
D. 16/5

Answer 1

let 5r be the radius and h be the height.
\[V1=\pi \left( 5r \right)^2h=25\pi r^2h\]
again \[radius=\frac{ 2 }{ 5 }\times 5 r=2r,height=4h\]
\[V2=\pi \left( 2r \right)^2\left( 4h \right)=16 \pi r^2 h\]
\[find \frac{ V2 }{ V1 }\]

Answer 2

Thank you so.

Answer 3

yw