The circumference of the base of a cylindrical vessel is $440\, cm$ and its height is $80\, cm$. Find the volume of the cylinder in $m^3$.

The surface area of a sphere and the curved surface area of a hemisphere are equal. Find the ratio of their radii.

$A$ storage tank is in the form of a cube. When it is full of water,the volume of water is $15.625 \, m^3$. If the present depth of water is $1.3 \, m$,find the volume of water already used from the tank (in $m^3$).

The radius and slant height of a conical vessel are $21 \,cm$ and $29 \,cm$ respectively. What is its capacity in litres?

If the total surface area of a cone is $3696 \, cm^{2}$ and the curved surface area of a cone is $2310 \, cm^{2}$,find the ratio of the radius to the slant height.

The ratio of the radii of a sphere and a hemisphere is $3:2$. Find the ratio of the surface area of the sphere to the total surface area of the hemisphere.