Question

Volume and surface area of a solid hemisphere are numerically equal. What is the diameter of hemisphere?
a) 1:3
b) 1:2
c) 3:1
d) 2:1

Answer 1

Answer:

Volume (Hemisphere)=  $\frac{2}{3} \pi r^{3}$

 Surface area=$3\pi r^{2}$

∴$3\pi r^{2}$ = $\frac{2}{3} \pi r^{3}$

⇒radius=  $\frac{9}{2}$

⇒diameter=$\frac{9}{1}$

Hence, the diameter of hemisphere is 9 units.

Option (c) is correct.