Question

the inner diameter of a circular well is 3.5m.it is 10 m deep. find (1) it's inner curved surface area (2)the cost of plastering the inner curved surface at their ate of Rs.40 per
${m}^{2}$
​

Answer 1

Answer:

Step-by-step explanation:

We know that the curved surface area of a right circular cylinder with radius r and height h is CSA=2πrh.

It is given that the height of the circular well is h=10 m and the diameter of the circular well is 2.8 m, and therefore the radius of the well is   2.8/2

=1.4 m, therefore,

CSA=2πrh=2×  22/7 ×1.4×10=  616/7  =88 m^2

 Therefore, the inner curved surface area is 88 m^2  .

Also, the cost of plastering curved surface per m^2   is Rs.42,  

Therefore, the cost of plastering 88 m^2  is:  Rs.42×88 m^2   = Rs.3696.

Hence, the inner curved surface area is 88 m^2  

 and the cost of plastering curved surface per m^2  

 is Rs.42 is Rs.3696.