Question

Ram Lakhan has a field in the form of circle. The cost of ploughing the field at the rate of $RS2.24$ per $m^2$ is $RS45056$. Find the cost of fencing the field at the rate of $RS12.60$per meter.

Answer 1

Rate of plowing $=2.24Rsper{m}^2$

Cost of plowing $=45056Rs$

To find the cost of fencing the field, if the rate of fencing is $12.60perm$

Area plowed for $Rs2.24=1m^2$

Area plowed for $Rs45056=\frac{1}{2.24}\times 45056m^2=20114.2857m^2$

Area of the circular field$=20114.2857m^2$

Let $r$ be the radius of the field.

$So,\pi r^2=20114.2857$

$r^2=20114.2857\times \frac{7}{22}$

$r^2=6400⟹r=80m$

Perimeter of the field $=2\pi r=2\times \frac{22}{7}\times 80=502.86m$

So, total cost of fencing $=502.86\times 12.60=6336Rs$