The inner diameter of a circular well is 3.5 m. It is 10 m deep Find:

(i) inner curved surface area.

(ii) the cost of plastering this curved surface at the rate of Rs. 40 per m².

Given,

Inner diameter of circular well = 3.5 m

Inner radius =

Depth of well = 10 m

i) Inner curved surface area of well = 2πrh = m²

ii) Cost of plastering 1m² area = Rs.40

Cost of plastering 110 m² = 40×110 = 4400 rs.