Find the curved surface area of a right circular cone whose slant height is $10\, cm$ and base radius is $7\, cm$. (in $, cm^{2}$)

The slant height and base diameter of a conical tomb are $25 \, m$ and $14 \, m$ respectively. Find the cost of white-washing its curved surface at the rate of $Rs. 210$ per $100 \, m^2$.

$A$ patient in a hospital is given soup daily in a cylindrical bowl of diameter $7 \, cm$. If the bowl is filled with soup to a height of $4 \, cm$, how much soup does the hospital have to prepare daily to serve $250$ patients?

Find the lateral or curved surface area of a closed cylindrical petrol storage tank that is $4.2\, m$ in diameter and $4.5\, m$ high. $\left[\text{Assume } \pi = \frac{22}{7}\right]$ (in $, m^2$)

$A$ hemispherical bowl has a radius of $3.5\, cm$. What would be the volume of water it would contain (in $, cm^{3}$)?

Twenty-seven solid iron spheres,each of radius $r$ and surface area $S$,are melted to form a single sphere with surface area $S'$. Find the ratio of $S$ to $S'$.