If the radius of the base and height of a cylinder and cone are each equal to r, and the radius of a hemisphere is also equal to r, then the volumes of the cone, cylinder and hemisphere are in the ratio ?

A. 1 : 2 : 3

B. 1 : 3 : 2

C. 2 : 1 : 3

D. 3 : 2 : 1

Answer: Option B

Solution(By Examveda Team)

Required ratio :
= Volume of cone : Volume of cylinder : Volume of hemisphere
$$\eqalign{ & = \frac{1}{3}\pi {r^2}:\pi {r^2}r:\frac{2}{3}\pi {r^3} \cr & = \frac{1}{3}:1:\frac{2}{3} \cr & = 1:3:2 \cr} $$