Question

The cost of cultivating a rectangular field at Rs 35 per square metre is Rs 71400. If the width of the field is 40 cm , find its length .Also, find the cost of fencing the field at Rs 50 per metre.

Answer 1

So you may know the formula of Area of rectangle. Here we have to find the area and not perimeter because the question describes above a field and fields consume the surface not the outline of the rectangular field.

So area of rectangle= (length * breadth)*35 (to find the cost)

Note: we are multiplying the area by 35 because it is mentioned that the cost of each square meter is 35.

Area of rectangle = Length*breadth*35
71400                  = length * 40*35
71400/35           = length*40
2040                  = length*40

So 2040 square meter is the area of the rectangular field.

Area of rectangle= length*breadth
2040                  = length*40
2040/40            = length
51                    = length

So the length of the rectangle is 51 m

To find the cost of fencing the field at 50 per meter we have to find the perimeter of the rectangle.

Perimeter of rectangle= 2(length+breadth)
                                   = 2(51+40)
                                   =  2(91)
                                  = 182 m

Now multiply it by 50 

182*50
=9100

the cost of fencing the field is rupees 9100.

Hope This Helps :)

Answer 2

Solution :

Perimeter :

I think we must first find perimeter i.e :

= 71400/35

= 2040

Length :

Then we have to find the length i.e. :

width is = 40

=2040/40

=51