Question

The cost of fencing a circular field at the rate of $Rs.240permetre$ is $Rs.52,800$ . The field is to be ploughed at the rate of $Rs.12.50per{m}^2$. Find the cost of ploughing the field.

• A. $Rs.48,125$
• B. $Rs.38,125$
• C. $Rs.10,125$
• D. $Rs.11,125$

Answer 1

The correct option is A $Rs.48,125$

Cost of fencing at the rate of Rs.$240$ per meter=$Rs.52800$
Therefore,
Circumference=$\frac{52800}{240}$
=$220$
Let r be the radius of the field
Therefore,
$2\pi r=220$
$=>r=\frac{220\times 7}{2\times 22}$
$=>r=35$
Therefore,
Area of the field=$\pi r^2$
=$\frac{22}{7}\times 35\times 35$
=$3850m^2$
Cost of fencing the field=$12.5\times 3850$
=$Rs.48125$