Correct Answer - Option 4 : 4,400
Given:
Number of cylindrical pillars = 40
Radius of each pillar = 35 cm = 0.35 m
Height of pillar = 5 m
Cost of painting the curved surface area of pillars at the rate of Rs. 10 per m2
Formula Used:
Curved Surface Area of cylindrical pillar = 2πrh
Calculation:
Curved Surface Area of one pillar = 2πrh
⇒ 2× 22/7 × 0.35 × 5
⇒ 11 m2
Total curved surface area of 40 pillars = 11 × 40 = 440 m2
∴ The total cost of painting the curved surface area of pillars ⇒ Rs. (440 × 10) = Rs. 4,400