The volume of a sphere is $4500 \pi \text{ cm}^3$,then its diameter is $\dots \text{ cm}$.

The curved surface area of a cylinder is $3960 \, cm^{2}$ and its volume is $41580 \, cm^{3}$. Find the radius and height of the cylinder.

The number of planks of dimensions $(4 \,m \times 50 \,cm \times 20 \,cm)$ that can be stored in a pit which is $16 \,m$ long,$12 \,m$ wide,and $4 \,m$ deep is:

$A$ 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.

For a given cylinder,the diameter of the base is $7 \,cm$ and its height is $12 \,cm$. Find the curved surface area of a cylinder (in $cm^2$).

$1$ hectare $= \ldots \ldots \text{ } m^{2}$