If the volume of a sphere is numerically equal to its surface area,then its diameter is ......... $cm$.

$2$ cubes,each of side $12\, cm$,are joined end-to-end. The surface area of the resulting cuboid is...........$cm^2$.

$3$ equal cubes are placed adjacently in a row. Find the ratio of the total surface area of the new cuboid to the sum of the surface areas of the three cubes.

Find the curved surface area (in $cm^{2}$) of a hemisphere of diameter $28\, cm$.

The base of a right prism is an equilateral triangle. If the lateral surface area and volume are $120 \, cm^2$ and $40 \sqrt{3} \, cm^3$,respectively,then the side of the base of the prism is ...... $cm$.

The radii of a cylinder and a cone are equal. If the height of the cylinder is equal to the slant height of the cone,then the ratio of the curved surface areas of the cylinder and the cone is: (in $:1$)