Question

Find the cost of painting 7 cylindrical pillars of a building at the rate of Rs. 40 per square metre. The diameter of a pillar is 50cm and its height is 6 metres

Answer 1

CSA of 1 pillar = 2 x 22/7 x 0.5/2 x 6
= 9.42 m^2
CSA of 7 pillar
= 7 x 9.42 = 65.94 m^2
Cost of painting
= 65.94 x 40
= 2637.6 rupees