Question

find the cost of plastering the curved surface of a well 8 m deep and 21 m in diameter at the rate of rupees 20 per m²​

Answer 1

Answer:

The cost of plastering the curved surface of a well 8 m deep and 21 m in diameter at the rate of rupees 20 per m² ​is Rs 10560.

Step-by-step explanation:

Given: Diameter = 21 m

radius = 21/2 m

Height of well = 8 m

Find the cost of plastering the curved surface of a well

The area of the curved surface will be = 2πr × h = 2πrh.

The curved surface area of well

$= 2 \times \frac{22}{7} \times \frac{21}{2} \times 8\\= 2 \times 11 \times 3 \times 8\\= 22 \times 24\\= 528 sq. m.$

So,  The curved surface area of well is 528 sq. m.

If the cost of plastering rate is Rs 20  per m²​

then the cost of plastering the curved surface of a well = 20 × 528 = 10560

So,  the cost of plastering the curved surface of a well is Rs 10560.