Question

The diameter of a roller is 91cm and its length is 1.6m it makes 600 revolution to level a field then find the cost of levelling at the rate of 70 paise per m square​

Answer 1

Hello..

Here's your answer..

Surface area of on revolution = 2∏rh 

= 2 x 22/ 7 x 60 x  84 

now for 500 revolution = 2 x 22/7 x 60 x 84 x 500

=1584 m2 

now cost leveling   1 m2 = Rs. 0.30

= for 1584 m2 = 0.30 x 1584 =  Rs. 475 . 20

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Answer 2

Given,

Diameter of a cylindrical roller = 91 cm

Length of the cylindrical roller = 1.6 m = 160 cm

Number of revolutions made by the roller to level a field = 600

Rate of cost of leveling the field = 70 paise/m^2

To find,

The total cost of leveling the field.

Solution,

We can simply solve this mathematical problem using the following process:

As per mensuration;

The lateral surface area of a cylinder

= 2π(radius of the circular base)(height of the cylinder)

Now, according to the question;

The total area of the field covered in each complete revolution of the roller

= lateral surface area of the cylindrical roller

= 2π(radius of the circular base)(height of the cylinder)

= 2π(radius of the circular base)(length of the cylinder)

= π(diameter of the circular base)(height of the cylinder)

(Since 2×radius = diameter)

= 22/7 × 91 cm × 160 cm

= 45,760 cm^2

= 4.576 m^2

(Since 100 cm = 1 m, that is, 10000 cm^2 = 1 m^2)

Now,

The total area of the field leveled

= total area of the field covered in 600 complete revolutions of the roller

= 4.576 m^2 × 600

= 2745.6 m^2

Now,

The total cost of leveling the field

= Total area of the field leveled × cost of leveling per square meter area

= 2745.6 m^2 × Rs. 0.7

(Since 100 paise = Re 1)

= Rs. 1921.92

= Rs. 1922 approx.

Hence, the total cost of leveling the field is approximately equal to Rs. 1922.