The $TSA$ (Total Surface Area) of a hemisphere with a diameter of $10 \, cm$ is $\ldots \ldots \ldots \, cm^2$. (in $\pi$)

The radii of the top and bottom of a bucket of slant height $45 \, cm$ are $28 \, cm$ and $7 \, cm$,respectively. The curved surface area of the bucket is (in $cm^2$)

How many balls of radius $1.4 \, cm$ can be produced by melting a metallic sphere of radius $42 \, cm$?

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

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

$A$ metallic cylinder with diameter $1 \, cm$ and height $4 \, cm$ is melted and recast to produce balls of radius $\frac{1}{8} \, cm$. Find the number of balls produced.