The radius of the base of a cone is $10 \, cm$ and its slant height is $26 \, cm$. Find the volume of the cone. $(\pi = 3.14)$ (in $cm^3$)

The volume of a solid cylinder is $4620 \, cm^{3}$ and its radius is $7 \, cm$. Find its height in $cm$.

The radius and slant height of a conical vessel are $7 \, cm$ and $25 \, cm$ respectively. What is its capacity in litres?

State whether the following statement is True or False and justify your answer: If the radius of a cylinder is doubled and its height is halved,the volume will be doubled.

$A$ hemispherical bowl of radius $18\, cm$ is completely filled with medicine. This medicine is to be filled in cylindrical bottles of radius $2\, cm$ and height $4\, cm$. How many bottles are required to empty the bowl?

Find the surface area of a sphere of diameter $3.5\,m$ (in $m^2$).