Question

The diameter of a circular park is $24m$. A $3m$ wide path runs around it from inside. Find the cost of paving the path at $Rs.25$ per square meter.

Answer 1

Since the Diameter$=24$m. The Radius will be $=D/2=24/2=12$m.

It is given that a $3$m wide path runs around it from 'inside'. Therefore, the Radius of the bigger circle will be $12-3=9$m

Area of bigger circle$=\pi r^2$

$=22/7^{\ast }{12}^{\ast }12=452.57m^2$

Area of smaller circle $=\pi r^2$

$=22/7^{\ast }{9}^{\ast }9=254.57m^2$

So the area of path $=$Area of bigger circle$-$Area of smaller circle

$=452.57-254.57$

$=198m^2$

The total cost$={198}^{ast}25=$Rs. $4950$.