Answer: C
Let the height of the solid hemisphere be equal to its radius = \(r\) units. \[ \therefore\ \text{The solid cone has base radius } r \text{ units and height } r \text{ units}. \] \[ \therefore\ \text{The ratio of their volumes is } \frac{2}{3} \pi r^3 : \pi r^2 \cdot r = \frac{2}{3} : 1 = 2 : 3 \]
Let the height of the solid hemisphere be equal to its radius = \(r\) units. \[ \therefore\ \text{The solid cone has base radius } r \text{ units and height } r \text{ units}. \] \[ \therefore\ \text{The ratio of their volumes is } \frac{2}{3} \pi r^3 : \pi r^2 \cdot r = \frac{2}{3} : 1 = 2 : 3 \]