The $TSA$ (Total Surface Area) of a $5$-rupee coin is given by the formula $\ldots \ldots \ldots . .$

The radii of a bucket in the shape of a frustum of a cone are $28 \, cm$ and $21 \, cm$. If its capacity is $28.490 \, \text{litres}$, find its height in $cm$.

The base of a cone with radius $15 \, cm$ and slant height $25 \, cm$ is hemispherical. Find the volume of this solid. $(\pi = 3.14)$ (in $cm^3$)

$A$ medicine capsule is in the shape of a cylinder of diameter $0.5\, cm$ with two hemispheres stuck to each of its ends. The length of the entire capsule is $2\, cm$. The capacity of the capsule is (in $cm^3$):

The volume of a sphere with radius $1.5 \text{ cm}$ is $\ldots \ldots \ldots \text{ cm}^3$.

$A$ metallic sphere with diameter $12 \, cm$ is melted and identical balls with radius $0.3 \, cm$ are produced. Find the number of balls produced.