Find the volume of a solid hemisphere whose diameter is 21…

Find the volume of a solid hemisphere whose diameter is 21 cm $(use \pi = {22 \over 7})$ .

Show answer & explanation

Correct answer: C

Explanation

The correct answer is option 3 i.e. 2425.5 cm³.

Radius r = D/2 = 21/2 = 10.5 cm

Volume of a hemisphere = 2/3 πr³

= $\frac{2}{3} \times \frac{22}{7} \times (10.5)^3$

$= \frac{2}{3} \times \frac{22}{7} \times 1157.625$

$= \frac{2}{3} \times 22 \times 165.375 = \frac{2}{3} \times 3638.25 = 2425.5 \,\text{cm}^3$

SSC Selection Post 2022 PYQ — Question 52