Question

1.
A cylindrical well is 21 m deep. Its outer and inner diameters are 21 m
14 m respectively. Find the cost of renovating the inner curved surface and o
curved surface at the rate of 25 per m².​

Answer 1

Answer:

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

Step-by-step explanation:

Answer 2

Step-by-step explanation:

please refer to the attachment

hope it helped