The radius of a cylinder is increased by $20 \%$,keeping its height unchanged. What is the percentage increase in its volume?

$A$ large solid sphere is melted and moulded to form identical right circular cones with base radius and height same as the radius of the sphere. One of these cones is melted and moulded to form a smaller solid sphere. Then the ratio of the surface area of the smaller to the surface area of the larger sphere is

Marbles of diameter $1.4\, cm$ are dropped into a cylindrical beaker containing some water and are fully submerged. The diameter of the beaker is $7\, cm.$ Find how many marbles have been dropped in it if the water rises by $5.6\, cm.$

$A$ hemisphere and a cone have equal bases. If their heights are also equal,the ratio of their curved surfaces will be

Surface area of a cube is $600\, cm^{2}$. Find out the length of its diagonal.

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 ...... $cm$.