A solid metal ball of radius 8 cm is melted and cast into smaller balls, each of radius 2cm. The number of such balls is

The volume of a sphere is 38808 cm³. Its surface area is

If the ratio of the volumes of two spheres is 1 : 8, then the ratio of their surface area is

A cone is 8.4 cm high and the radius of its base is 2.1 cm. It is melted and recast into a sphere. The radius of the sphere is

A solid lead ball of radius 6 cm is melted and then drawn into a wire of diameter 0.2 cm. The length of wire is