A ball is dropped from a height of 10 m. It strikes the ground and rebounds up to a height of 2. m. During the collision, the per cent loss in the kinetic energy is
A right circular conical structure stands on a circular base of 21m diameter and is 14m in height. The total cost of colour washing for its curved surface at Rs. 6 per sq. m. is (Take Π = 22/7 )