$A$ hemispherical bowl of radius $18\, cm$ is completely filled with medicine. This medicine is to be filled in cylindrical bottles of radius $2\, cm$ and height $4\, cm$. How many bottles are required to empty the bowl?

$A$ 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?

$A$ 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 $, cm^2$)?

The curved surface area of a cylinder is $3960\, cm^{2}$. If its radius is $21\, cm$,find its height in $cm$.

The thickness of a metallic tube is $5 \, mm$ and the inner diameter of the tube is $10 \, cm$. Find the mass of a $70 \, cm$ long tube,if the density of the metal is $8 \, g/cm^3$. (in $g$)

Find the curved surface area and the total surface area of a hemisphere with a diameter of $126 \, cm$.