Question

A rope is used to cover an open cylindrical tank of a radius of 9.8 m and height of 10 m. The cost of rope is Rs. 5 per sq. m. Find the total cost of rope used in covering the tank. (Take π = 22/7)

1. Rs. 3080
2. Rs. 6,343
3. Rs. 1,085
4. Rs. 5,092

Answer 1

Correct Answer - Option 1 : Rs. 3080

Given:

The radius of cylindrical tank = 9.8 m

Height of cylinder = 10 m

Cost of 1 m³ rope = Rs. 5

Concepts used:

The covered surface area of cylinder = 2πrh

Where,

r → Radius of cylinder 

h → Height of cylinder 

Calculation:

Length of rope used to cover cylindrical tank = Surface area of the tank

⇒ 2 × 22/7 × 9.8 × 10 = 616 m²

Cost of rope = Cost of 1 m² rope × Surface area of the tank

⇒ Rs. 5 × 616

⇒ Rs. 3080

∴ The cost of rope used to cover the cylindrical tank is Rs. 3080.