A solid sphere of radius $6 \mathrm{cm}$ is melted into a hollow cylinder of uniform thickness. If the external radius of the base of the cylinder is $5 \mathrm{cm}$ and its height is $32 \mathrm{cm},$ then find the thickness of the cylinder.

The curved surface area of a right circular cone of height $15 \mathrm{cm}$ and base diameter $16 \mathrm{cm}$ is _____.

If two solid hemispheres of same base radius $r$units are joined together along with their bases, then the curved surface area of this new solid is

The height of a right circular cone whose radius is $5 \mathrm{cm}$ and slant height is $13 \mathrm{cm}$ will be _____.

If the radius of the base of a right circular cylinder is halved keeping the same height, then the ratio of the volume of the cylinder thus obtained to the volume of the original cylinder is 

The total surface area of a cylinder whose radius is $\frac{1}{3}$ of its height is _____.

In a hollow cylinder, the sum of the external and internal radii is $14 \mathrm{cm}$ and the width is $4 \mathrm{cm}$. If its height is $20 \mathrm{cm}$, the volume of the material in it is _____.

If the radius of the base of a cone is tripled and the height is doubled then the volume becomes _____.