Answer:
Option B
Explanation:
Let r1 be the radius of the hemishere and r2 be the radius of the cone.
Volume of hemisphere = Volume of cone
$\frac{2}{3}\pi (r1)^{3}=\frac{1}{3}\pi (r2)^{2}h$
$\Rightarrow \frac{2}{3}\pi (6)^{3}=\frac{1}{3}\pi (r2)^{2}\times 75 $ $\Rightarrow (r2)^{2}=\frac{3}{75} \times \frac{2}{3}\times (6^{3})$
$=\frac{2}{25\times 3} \times 6\times 6\times 6$ $\Rightarrow r2=\frac{12}{5}=2.4 cm$
