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 $cm^2$).

The water for a factory is stored in a hemispherical tank whose internal diameter is $14\, m$. The tank contains $50\, kilolitres$ of water. Water is pumped into the tank to fill it to its capacity. Calculate the volume of water pumped into the tank (in $m^3$).

Each of the radius of a cylinder and a sphere is $9 \, cm$. If the volumes of these solids are equal,find the height of a cylinder (in $cm$).

$A$ right triangle with sides $6 \, cm$,$8 \, cm$,and $10 \, cm$ is revolved about the side $8 \, cm$. Find the curved surface area of the solid so formed (in $cm^2$). (in $, cm^2$)

The surface area of a sphere is $7850 \, cm^2$. Find its radius in $cm$. (Use $\pi = 3.14$)

The radius and slant height of a cone are $10 \, cm$ and $25 \, cm$ respectively. Find the total surface area of a cone. (in $cm^2$)