Question

A circular pond is of diameter 17.5 m. It is surrounded by a 2 m wide path. Find the cost of constructing the path at the rate of Rs. 25 per square metre (Use $\pi =3.14$).

Answer 1

Radius of the circular pond, $r=\frac{17.5}{2}=8.75m$

Outer radius $=8.75+2=10.75m$

So, area of the path = $\pi ({10.75}^2-{8.75}^2)=\frac{22}{7}\times ({10.75}^2-{8.75}^2)=122.57m^2$

Cost of constructing it = Rs. 25 $\times$ 122.57 = Rs. 3064.25