Volume of a hemisphere is 19404 cu. cm. Its radius is · ABC26GN5042
Subject: General Aptitude · Chapter: Volume and Surface Area
Volume of a hemisphere is 19404 cu. cm. Its radius is
(a)10.5 cm
(b)17.5 cm
(c)21 cm
(d)42 cm
Answer
Answer (as printed): C
Explanation
Let the radius be $R$ cm. Then, $\frac{2}{3} \times \frac{22}{7} \times R^{3}=19404 \Leftrightarrow R^{3}=\left(19404 \times \frac{21}{44}\right)=(21)^{3}$ $$\Leftrightarrow R=21 \mathrm{cm} .$$