If the radius if a sphere is 2r, then its volume will be

The total surface area of a cube is 96 cm². The volume of the cube 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

In a cylinder, radius is doubled and height is halved, then curved surface area will be

The total surface area of a cone whose radius is r/2 and slant height 2L is