The area of the base of a cylinder is equal to:

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

The rainwater from a roof of dimensions $22 \, m \times 20 \, m$ drains into a cylindrical vessel having a base diameter of $2 \, m$ and a height of $3.5 \, m$. If the rainwater collected from the roof just fills the cylindrical vessel,find the rainfall in $cm$.

$A$ cylinder with radius $21 \, cm$ and height $18 \, cm$ is closed at both the ends by hemispheres. Find the surface area of this article. $(\pi = \frac{22}{7})$ (in $cm^2$)

$A$ sphere and a solid hemisphere have equal radii. Then,the ratio of the surface area of the sphere and $TSA$ of the hemisphere is $\ldots \ldots \ldots \ldots$

Write 'True' or 'False' and justify your answer:
The capacity of a cylindrical vessel with a hemispherical portion raised upward at the bottom as shown in the figure is $\frac{\pi r^{2}}{3} [3 h-2 r]$.