Question

mm
The diameter of a cylindrical well is 4.5 m and
depth of the well is 14 m. Find the cost of it
cementing its inner curved surface at the rate of
₹12.50 per sq. metre.​

Answer 1

(i)r= radius=  

2

3.5

​  

=1.75 , h= depth of the well=10m  

⇒Curved surface area  

=2πrh

=(2×  

7

22

​  

×1.75×10)m  

2

=110m  

2

 

⇒(ii) Cost of plastering = Rs 40 per m  

2

 

The cost of plastering the curved surface = Rs (110×40)= Rs 4400.