The length,breadth,and height of a cuboid are $20\, cm$,$15\, cm$,and $12\, cm$ respectively. Find its total surface area (in $cm^2$).

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 $, m^2$)

The length,breadth,and height of a hall are $7\, m$,$5\, m$,and $4\, m$ respectively. It has two doors measuring $3\, m \times 2\, m$ each and four windows measuring $2\, m \times 1\, m$ each. Find the cost of whitewashing all the four walls and the ceiling of the hall at the rate of ₹$200$ per $m^2$.

The ratio of the curved surface area and the total surface area of a cylinder is $2: 5$. Find the ratio of the radius and height of the cylinder.

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

$A$ 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 $, cm^2$)