Diameter of the base of a cone is $10.5\, cm$ and its slant height is $10\, cm$. Find its curved surface area. Assume $\pi = \frac{22}{7}$. (in $, cm^2$)

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

The inner diameter of a circular well is $3.5 \, m$. It is $10 \, m$ deep. Find its inner curved surface area. [Assume $\pi = \frac{22}{7}$] (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 $4.4 \, cm$ (see Fig.). Find its total surface area. (in $, cm^2$)

$A$ conical pit of top diameter $3.5 \, m$ is $12 \, m$ deep. What is its capacity in kilolitres (in $kl$)?

$A$ 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 $, cm^2$)?