The radius and height of a cone are both $3 \, cm$. Then,its volume is $\ldots \ldots \ldots \, cm^{3}$. (in $\pi$)

The shape of a glass (tumbler) (see figure) is usually in the form of:

The radius of a cone is $15 \, cm$ and its base is hemispherical. If the total height of the solid is $55 \, cm$,find its volume in $cm^3$.

Write 'True' or 'False' and justify your answer:
$A$ solid cylinder of radius $r$ and height $h$ is placed over another cylinder of the same height and radius. The total surface area of the shape so formed is $4 \pi r h + 4 \pi r^2$.

The volume of a cylinder with radius and height both $5 \, cm$ is $\ldots \ldots \ldots \pi \, cm^{3}$.

Volumes of two spheres are in the ratio $64: 27$. The ratio of their surface areas is