The volume of a right circular cone is $9856 \, cm^3$. If the diameter of the base is $28 \, cm$,find the height of the cone. (in $, cm$)

$A$ cylindrical pillar is $50 \, cm$ in diameter and $3.5 \, m$ in height. Find the cost of painting the curved surface of the pillar at the rate of $Rs. \, 12.50$ per $m^2$. $\left[ \text{Assume } \pi = \frac{22}{7} \right]$

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 $S'$.

Find the surface area of a sphere of radius $14 \, cm$.
Assume $\pi = \frac{22}{7}$. (in $, cm^2$)

The volume of a right circular cone is $9856 \, cm^3$. If the diameter of the base is $28 \, cm$,find the slant height of the cone. (in $, cm$)

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