Question

the outer radius of a pipe is 12.5 cm and it is 21 m long find the cost of painting the outer surface @ rupees 50 per metre square

Answer 1

hope this helps.....

Answer 2

The cost will be ₹82.5

Given data :

• Outer radius of the given pipe = 12.5 cm = 0.125 m [ Term of unit conversion is 100 cm = 1 m]

Height of the given pipe = 21 m

The rate of the painting = ₹ 50 / m²

• Now,we have calculate the surface area of the given pipe by using the following formula :

2 × π × radius of the given pipe × height of the given pipe

So,

The surface area of the given pipe = (2×π×radius×height) = {2×(22/7)×0.0125×21) = 1.65 m²

• At last we have to calculate the total painting cost of the calculated surface area of the given pipe.

Now,

1 m² painting cost = 50 rs.

1.65 m² painting cost = (50×1.65) =₹ 82.5

So the total painting cost of the given pipe ₹82.5 (answer)