Radius of cylinder (r) = 25cm = 0.25m (1 m =100 cm)
Height of cylinder (h) = 3.5m
Curved surface area of cylinder = 2πrh
Cost of painting 1 sq m = Rs.15.50
Cost of painting 38.5 sq m = Rs.15.50 × 5.5 = Rs. 85.25
Cost of painting 10 such columns = Rs. 85.25 × 10 = Rs. 852.5