Q : 7 The inner diameter of a circular well is . It is deep. Find
(ii) the cost of plastering this curved surface at the rate of Rs 40 per .
Given,
Inner diameter of the circular well =
Depth of the well =
The inner curved surface area of the circular well is
Now, the cost of plastering the curved surface per = Rs. 40
Cost of plastering the curved surface of =
Therefore, the cost of plastering the well is