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 $:1$)

Consider the volumes of the following:
$1.$ $A$ parallelepiped of length $5\,cm$,breadth $3\,cm$ and height $4\,cm$.
$2.$ $A$ cube of each side $4\,cm$.
$3.$ $A$ cylinder of radius $3\,cm$ and length $3\,cm$.
$4.$ $A$ sphere of radius $3\,cm$.
The volumes of these in decreasing order are:

The radius of a cylinder is half its height and the curved surface area is $616 \, cm^{2}$. Approximately how many litres of milk can it contain?

The numerical values of the volume and the area of the lateral surface of a right circular cone are equal. If the height of the cone is $h$ and the radius is $r,$ the value of $\frac{1}{h^{2}}+\frac{1}{r^{2}}$ is

The slant height of a right circular cone is $10 \, m$,and its height is $8 \, m$. Find the area of its curved surface (in $\pi \, m^2$).

Three solid spheres have their radii $r_{1}, r_{2}$ and $r_{3}$. The spheres are melted to form a single solid sphere of a bigger radius. The radius of the new sphere is: