Question

The total cost of fencing a field is Rs. 1200 at the rate of Rs. 5 per
metre.Ifthe length of the field is 72 m, what is the breadth of the field?​

Answer 1

Answer:

48m is the answer of this question

Answer 2

Answer :

• The breadth of the rectangle , b = 48 m.

Explanation :

Given :

• Total cost of fencing the field = Rs. 1200.

• Cost of fencing the field per metre = Rs. 5

• Length of the field , l = 72 m.

To find :

• Breadth of the rectangle , b = ?.

Knowledge required :

• Formula for perimeter of the field when the total cost and cost per metre is given.

We know that ,

"Total cost of fencing the field is the product of its perimeter and the cost of fencing per metre."i.e,

Total cost of fencing = Perimeter × cost per metre.

From the above information , we can conclude that :

Perimeter = Total cost ÷ cost per metre

Hence by the above equation, we can find the Perimeter of the field.

• Formula for perimeter of a Rectangle :

⠀⠀⠀⠀⠀⠀⠀⠀⠀P = 2(l + b)

Where :

• P = Perimeter of the rectangle.
• l = Length of the rectangle.
• b = Breadth of the rectangle.

Solution :

By using the formula for perimeter of a rectangle , when the total cost and the cost per metre is given , and by substituting the values in it , we get :

==> Perimeter = Total cost ÷ cost per metre

==> P = 1200/5

==> P = 240

∴ P = 240 m

Hence the perimeter of the rectangle is 240 m.

Now to the find the breadth of the rectangle ,

By using the formula for perimeter of a rectangle and substituting the values in it , we get :

==> P = 2(l + b)

==> 240 = 2(72 + b)

==> 240 = 144 + 2b

==> 240 - 144 = 2b

==> 96 = 2b

==> 96/2 = b

==> 48 = b

∴ b = 48 m.

Therefore,

• The breadth of the rectangle , b = 48 m.