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` 

Answer 1

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