Question

A mansion has 12right cylindrical pillars each having radius 50cm and height 3.5 m.Find the cost to paint the lateral surface of the pillars at ₹20 per square metre.

Answer 1

Surface area of 12 pillars is132 sq mt
Cost=132*12=2640

Answer 2

No. of pillars = 12

r = 50cm           h = 3.5m

= 0.5m

Rate=20rs/m²

C.S.A= 2πrh

        =2*22/7*3.5*0.5

        =2*22/7*3.5*1/2

        =11m²

C.S.A of 12 such pillars = 11*12

                                      = 132m²

Cost for painting 12 such walls = Total C.S.A*Rate

                                                   = 132*20

                                                   = Rs 2,640

Hope this helps.........<3