Subject: General Aptitude · Chapter: Volume and Surface Area · Exam: 2006 · Marks: · Difficulty:
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
Answer (as printed): B
Explanation
Required ratio = Volume of cone : Volume of cylinder : Volume of hemisphere $$=\frac{1}{3} \pi r^{2} r: \pi r^{2} r: \frac{2}{3} \pi r^{3}=\frac{1}{3}: 1: \frac{2}{3}=1: 3: 2 .$$
Explanation as extracted from the printed page; notation may be imperfect.