$A$ cylindrical tank is closed at both the ends by hemispheres. The diameter of the tank is $24 \, cm$ and the total height is $78 \, cm$. How many litres of kerosene can it hold?

$A$ metallic sphere of radius $21 \,cm$ is melted and recast to form a wire with diameter $0.5 \,cm$. Find the length of the wire in $m$.

$A$ metallic spherical shell of internal and external diameters $4 \, cm$ and $8 \, cm$,respectively,is melted and recast into the form of a cone of base diameter $8 \, cm$. The height of the cone is (in $cm$):

The surface area of a sphere is $\ldots \ldots$

$1\,m^3 = \dots \dots \dots cm^3$.

$A$ rectangular water tank of base $11 \,m \times 6 \,m$ contains water up to a height of $5 \,m$. If the water in the tank is transferred to a cylindrical tank of radius $3.5 \,m$,find the height of the water level in the tank. (in $m$)