Subject: General Aptitude · Chapter: Volume and Surface Area · Exam: 2006 · Marks: · Difficulty:
The ratio of the volumes of a hemisphere and a cylinder circumscribing this hemisphere and having a common base is
(a)1 : 2
(b)2 : 3
(c)3 : 4
(d)4 : 5
Answer
Answer (as printed): B
Explanation
Let the radius of the hemisphere be $r \mathrm{cm}$. Then, radius of the cylinder $=r \mathrm{cm}$. height of the cylinder $=r \mathrm{cm}$. $$\text { ∴ } \text { Required ratio }=$$ $\frac{\text { Volume of hemisphere }}{\text { Volume of cylinder }}=\frac{\frac{2}{3} \pi r^{3}}{\pi r^{2} \times r}=\frac{2}{3}$.