Question

find the cost of painting 15 cylindrical pillar of the building at rupees 2.50 per square metre if the diameter and height of each pillar are 48 centimetre and 7 metres respectively

Answer 1

Radius of pillar = 48/2 = 24 cm =0.24m
height of pillar = 7 m
Rate of painting = ₹2.50 per meter square

C.S.A of one pillar = 2πrh
= 2×(22/7)×0.24×7
= 10.56 m sq.

Cost of painting 15 pillars
= 15 × C.S.A × Rate
= 15× 10.56 × 2.5
= 396Rs.