Question

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

Answer 1

Total cost of cultivating the field =$Rs.71400$

Rate of cultivating the field = $Rs.35$ per square metre

Therefore,

Area of the filed = $\frac{\text{Total cost of cultivating}}{\text{Cost of cultivating per square metre}}=\frac{71400}{35}=2040$ sq. m

Now, length of the field = $40$ m

Let $b$ m be the breadth of the field.

$\therefore$ Area of the filed = Length $\times$ Breadth = $40b$ sq. m

ATQ,

$40b=2040$

$\Rightarrow b=\frac{2040}{40}=51$

Hence, breadth of the field is $51$ m.

Now,

Perimeter of the field = $2(l+b)=2\times (51+40)=182$ m

Therefore, cost of fencing the field at $Rs.50$ = $182\times 50=Rs.9100$