The radius of a cylinder is $10\, cm$ and its curved surface area is $440\, cm^{2}$. Then its height is $\ldots \ldots \ldots$

$A$ school provides milk to the students daily in cylindrical glasses of diameter $7 \, cm$. If the glass is filled with milk up to a height of $12 \, cm$, find how many litres of milk is needed to serve $1600$ students.

$A$ well,$20 \, m$ deep,is $7 \, m$ in radius. Find the cost of cementing the inner curved surface at the rate of ₹ $15$ per $m^2$. (in ₹)

The radius of a sphere is $6\, cm$. It is melted and drawn into a wire of diameter $1\, cm$. Find the length of the wire (in $m$).

$A$ 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 curved surface area of a cylinder is $1320 \, cm^2$. If its height is $30 \, cm$,find its diameter (in $cm$).