Question

A cylindrical pillar is 50 cm in diameter and 3.5 m in height. Find the cost of painting the curved surface of the pillar at the rate of Rs.12.50 per m².

`["Assume "pi=22/7]`

 

Answer 1

Height (h) cylindrical pillar = 3.5 m

Radius (r) of the circular end of pillar = 50/2 = 25cm = 0.25m

CSA of pillar = 2πrh

`=(2xx22/7xx0.25xx3.5)m^2`

`=(44xx0.125)m^2`

 = 5.5 m²

Cost of painting 1 m² area = Rs 12.50

Cost of painting 5.5 m² area = Rs (5.5 × 12.50)

= Rs 68.75

Therefore, the cost of painting the CSA of the pillar is Rs 68.75.