Question

0. In a building there are 25 cylindrical pillars. The diameter of each pillar is 56 cm and
height is 7m. Find the total cost of painting the curved surface area of all pillars at the
rate of Rs. 20 per metre square.​

Answer 1

Answer:

For one cylindrical pillar, Radius (r) = 28 cm. Height (h) = 4 m = 4 x 100 cm. = 400 cm. ∴ Curved surface area of 1 pillar = 2πrh = 2 x 22/7 x 28 x 400 = 70,400 cm2 ∴ Curves surface area of 25 cylindrical pillars = 70400 x 25 = 1760000 cm2 = 1760000/10000 m2 = 176 m2 ∴ Cost of 25 cylindrical pillars painting = 176 x 8 = Rs 1408