$A$ joker's cap is in the form of a right circular cone of base radius $7\, cm$ and height $24\, cm$. Find the area of the sheet required to make $10$ such caps. (in $, cm^2$)

Find the amount of water displaced by a solid spherical ball of diameter $28 \, cm$.

$A$ small indoor greenhouse (herbarium) is made entirely of glass panes (including base) held together with tape. It is $30 \, cm$ long,$25 \, cm$ wide and $25 \, cm$ high. What is the area of the glass (in $, cm^2$)?

$A$ 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 inner curved surface area. (in $, cm^{2}$)

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

The inner diameter of a cylindrical wooden pipe is $24 \, cm$ and its outer diameter is $28 \, cm$. The length of the pipe is $35 \, cm$. Find the mass of the pipe,if $1 \, cm^3$ of wood has a mass of $0.6 \, g$. (in $, kg$)