Question

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

Answer 1

Answer:

Rs 57750

Step-by-step explanation:

The cost of renovating the inner curved surface area and the outer curved surface area is Rs.57750.

Step-by-step explanation:

Given : Andy cylindrical well 21 meter deep. Its outer and inner diameters are 21 m and 14 m respectively.

To find : The cost of the renovating the inner curved surface area and the outer curved surface area at the rate of rs 25 per meter square?

Solution :

The outer diameter of the cylinder 21 meter.

The outer radius of the cylinder = 21/2=10.5 m

The inner diameter of the cylinder 14 meter.

The inner radius of the cylinder = 14/2=7 m

Height is 21 m.

Curved surface area of the inner cylinder is C_i=2\pi r hCi=2πrh

C_i=2\times \frac{22}{7}\times 7\times 21Ci=2×722×7×21

C_i=924Ci=924

Curved surface area of the outer cylinder is C_i=2\pi R hCi=2πRh

C_o=2\times \frac{22}{7}\times 10.5\times 21Co=2×722×10.5×21

C_o=1386Co=1386

Total curved surface area is

TSA=C_i+C_oTSA=Ci+Co

TSA=924+1386TSA=924+1386

TSA=2310TSA=2310

Cost of per meter square is Rs.25.

Cost of renovating the inner curved surface area and the outer curved surface area is

C=2310\times 25C=2310×25

C=57750C=57750

Therefore, The cost of renovating the inner curved surface area and the outer curved surface area is Rs.57750.

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