Question

Andy cylindrical well 21 metre deep. its outer and inner diameters are 21 m and 14 m respectively. find the cost of the renovating the inner curved surface area and the outer curved surface area at the rate of rs 25 per metre square

Answer 1

ur ans is in the attachment

Answer 2

Answer:

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 $C_i=2\pi r h$

$C_i=2\times \frac{22}{7}\times 7\times 21$

$C_i=924$

Curved surface area of the outer cylinder is $C_i=2\pi R h$

$C_o=2\times \frac{22}{7}\times 10.5\times 21$

$C_o=1386$

Total curved surface area is

$TSA=C_i+C_o$

$TSA=924+1386$

$TSA=2310$

Cost of per meter square is Rs.25.

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

$C=2310\times 25$

$C=57750$

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