The thickness of a cylinder is 1 foot, the inner radius of the cylinder is 3 feet and height is 7 feet. To paint the inner surface it requires one litre of a particular colour. How much quantity of the same colour is required to paint all the surfaces of the cylinder?

The thickness of a cylinder is 1 foot, the inner radius of the cylinde

1.	The thickness of a cylinder is 1 foot, the inner radius of the cylinder is 3 feet and height is 7 feet. To paint the inner surface it requires one litre of a particular colour. How much quantity of the same colour is required to paint all the surfaces of the cylinder?
A.	\(\frac{7}{3}litre\)
B.	\(\frac{3}{2}litre\)
C.	\(\frac{8}{3}litre\)
D.	\(\frac{10}{3}litre\)
Answer» D. \(\frac{10}{3}litre\)