The volume of a cylinder is $550 \, cm^3$ and its radius is $5 \, cm$. Then,its height is ....... $cm$.

$A$ cone of radius $4 \, cm$ is divided into two parts by drawing a plane through the midpoint of its axis and parallel to its base. Compare the volumes of the two parts.

The radii of a frustum of a cone are $28 \, cm$ and $7 \, cm$ and its height is $72 \, cm$. Find its curved surface area,total surface area,and volume.

$A$ solid toy is in the form of a hemisphere surmounted by a right circular cone. The height of the cone is $2 \, cm$ and the diameter of the base is $4 \, cm$. Determine the volume of the toy. If a right circular cylinder circumscribes the toy,find the difference of the volumes of the cylinder and the toy. (in $cm^3$) (Take $\pi = 3.14$)

$1 \, m^3 = \dots \text{liters}$

$A$ $20\, m$ deep well with diameter $7\, m$ is dug and the earth from digging is evenly spread out to form a platform $22\, m$ by $14\, m$. Find the height of the platform. (in $m$) [Take $\pi=\frac{22}{7}$]