Question

A cylindrical pillar is 50cm in diametre and 3.5m in height.The cost of painting the curved surface of the pillar at the rate of RS 10 per metre square is...(take pi=22/7)

Answer 1

As we know that,

CSA of cylinder =2πrh

Radius of a pillar =14cm=0.14m

Height of pillar =1m

CSA of 1 pillar =2×

7

22

×0.14×1

=44×0.02=0.88m

2

CSA of 20 pillars =0.88×20=17.6m

2

Cost of painting per meter square =Rs.10

Therefore,

Cost of painting 17.6m

2

=17.6×10=Rs.176