Answer: B
The radius of the base of both the hemisphere and the cone is \(r\) And the height of both is equal to the radius of the hemisphere, i.e., \(r\) \(\therefore\) The ratio of the volumes of the hemisphere and the cone is \(= \cfrac{2}{3}\pi r^3 : \pi r^2 \cdot r\) \(= \cfrac{2}{3}\pi r^3 : \pi r^3\) \(= \cfrac{2}{3} : 1\) \(= 2 : 3\)
The radius of the base of both the hemisphere and the cone is \(r\) And the height of both is equal to the radius of the hemisphere, i.e., \(r\) \(\therefore\) The ratio of the volumes of the hemisphere and the cone is \(= \cfrac{2}{3}\pi r^3 : \pi r^2 \cdot r\) \(= \cfrac{2}{3}\pi r^3 : \pi r^3\) \(= \cfrac{2}{3} : 1\) \(= 2 : 3\)