Question

If the radius of the base of a right circular cylinder is halved, keeping the height same, what is the ratio of the volume of the reduced cylinder to that of the original.

• A. $1:3$
• B. $1:5$
• C. $1:4$
• D. $1:7$

Answer 1

Answer: (C)

$1:4$

circular cylinder's radius=r
height=h
keeping the height same, radius is halved
radius of new circular cylinder=r/2
So, ratio of volume = volume of reduced cylinder/volume of original cylinder
$Ratio=\Pi {r/2}^{2}h/\Pi {\left(r\right)}^{2}h$
$Ratio=1/4$