How many litres of milk can a hemispherical bowl of diameter $10.5\, cm$ hold (in $, l$)?

The capacity of a closed cylindrical vessel of height $1 \, m$ is $15.4$ litres. How many square metres of metal sheet would be needed to make it (in $, m^{2}$)?

$A$ metal pipe is $77 \,cm$ long. The inner diameter of a cross section is $4 \,cm$ and the outer diameter is $4.4 \,cm$. Find its outer curved surface area. (in $,cm^{2}$)

Find the surface area of a sphere with a diameter of $3.5 \, cm$. Assume $\pi = \frac{22}{7}$. (in $, cm^2$)

At a Ramzan Mela,a stall keeper in one of the food stalls has a large cylindrical vessel of base radius $15 \, cm$ filled up to a height of $32 \, cm$ with orange juice. The juice is filled in small cylindrical glasses (see figure) of radius $3 \, cm$ up to a height of $8 \, cm$,and sold for $Rs. 15$ each. How much money does the stall keeper receive by selling the juice completely?

Twenty-seven solid iron spheres,each of radius $r$ and surface area $S$,are melted to form a single sphere with surface area $S'$. Find the ratio of $S$ to $S'$.