CBSE Class 9 Answered
The inner radius of a circular well is 2.1 m and its depth is 21 m. Find the cost of plastering the inner surface of a circular well at the rate of Rs. 40 per m2
Given: Radius of the circular well (r) = 2.1 m, depth (h) = 21 m
Let S denote the inner surface of the well which is the sum of Curved surface area and Area of the base.
Cost of 1 m2 of sheet = Rs. 40
Cost of 291.06 m2 of sheet = Rs. (40 × 291.06) = Rs. 11642.40