Question

A well of diameter 7m and height 20m is dugout. find the cost of plastering the Curve surface of the well at the rate of ₹20 per m²​

Answer 1

Answer:

A well of diameter 7m and height 20m is dugout. The cost of plastering the Curve surface of the well at the rate of ₹20 per m²​ is ₹ 8800.

Step-by-step explanation:

Given: Diameter of dugout = 7 m

And the height of dugout = 20m

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

Diameter (d) = 7 m

radius (r) = 7/2 = 3.5 m

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

$= 2 \times \frac{22}{7} \times 3.5 \times 20\\= 2 \times 22 \times 0.5 \times 20\\= 44 \times 10\\= 440 sq. m.$

So, the curve surface of the well is 440 sq. m.

If Curve surface of the well at the rate of ₹20 per m²​

Then the cost of plastering = 440 × 20 = ₹ 8800