If the ratio of the radii of two spheres is 3 : 7, find :

(i) the ratio of their volumes.

(ii) the ratio of their surface areas.

If the ratio of the volumes of the two spheres is 125 : 64, find the ratio of their surface areas.

A hemispherical bowl has a radius of 3.5 cm. What would be the volume of water it would contain ?