Question

a cylindrical well is 21 m deep. its outer and inner diameter are 21 m and 14 respectively. find the cost of renovating the inner curved surface and outer curved surface at the rate of rs25 per m^2

Answer 1

Thanks for asking this question............hope it helps

Answer 2

According to me this must be the solution

h=21m
outer r =21÷2=10.5m
inner r = 14÷2=7m

Inner CSA= 2Πrh
2*22/7*7*21. =924m^2

Outer CSA = 2*22/7*10.5*21
= 1386m^2

Cost of renovating Inner CSA = 25*924=Rs 23100
Cost of renovating Outer CSA= 25*1386=Rs 34650