Find the surface area of a sphere of radius $10.5 \, cm$.
Assume $\pi = \frac{22}{7}$. (in $, cm^{2}$)

$A$ wall of length $10\, m$ was to be built across an open ground. The height of the wall is $4\, m$ and thickness of the wall is $24\, cm$. If this wall is to be built up with bricks whose dimensions are $24\, cm \times 12\, cm \times 8\, cm$,how many bricks would be required?

It costs $Rs. 2200$ to paint the inner curved surface of a cylindrical vessel $10 \, m$ deep. If the cost of painting is at the rate of $Rs. 20$ per $m^2$,find the inner curved surface area of the vessel. (in $, m^2$)

Find $(i)$ the curved surface area and $(ii)$ the total surface area of a hemisphere of radius $21\, cm$.

If the lateral surface area of a cylinder is $94.2 \, cm^2$ and its height is $5 \, cm$,then find the radius of its base. (in $, cm$)

$A$ 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 $, cm^2$)?