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Question
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 m^2`
Solution
Inner radius (r) of circular well=1.75m
Depth (n) of circular well =10m
(1) Inner curved surface area = `2pirh`
=`2xx22/7xx1.75xx10m^2`
=`(144xx0.25xx10)m^2`
=110m^2
(2) Cost of plastering `1m^2` area = Rs.40.
Cost of plastering `110m^2` area= Rs (100xx40)
=Rs.4400
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