The total surface area of a closed cylinder is $748\, cm^2$. If its radius is $7\, cm$,find its height (in $cm$).

Write True or False and justify your answer.
An edge of a cube measures $r \, cm$. If the largest possible right circular cone is cut out of this cube,then the volume of the cone (in $cm^3$) is $\frac{1}{6} \pi r^3$.

The radius and the slant height of a cone are in the ratio $4: 7$. The ratio of its total surface area to its curved surface area is $\ldots \ldots \ldots$

The radius of the base of a cone is $14 \, cm$ and its slant height is $50 \, cm$. Find the volume of the cone (in $cm^3$).

Find the surface area of a sphere of radius $1.25 \, m$ $(\pi = 3.14)$ (in $m^2$).

The radius of a sphere is $14 \, cm$. Find its surface area (in $cm^2$).