Correct option is: C) 21
Let the radius of the hemisphere be r.
\(\therefore\) Volume of the hemisphere = \(\frac 23 \pi r^3\)
Given that the volume of hemisphere is 19404 \(cm^3\)
\(\therefore\) \(\frac 23 \pi r^3\) =19404
= \(r^3 = 19404 \times \frac 32 \times \frac 7{22} = 441 \times 21 = 21^3\)
\(\therefore\) r = 21 cm
Hence, the radius of the hemisphere is 21 cm.
