Question

Diameter of a circular pond is 17.5m it is surrounded by a 2m wide path. Find the cost of constructing the path at the rate of rs 25per m.

Answer 1

area of path=pi. {R^2-r^2}
R=17.5/2+2=8.75+2=10.75
r=8.75
now area of path =22/7 x ({10.75)^2-(8.75)^2=22/7 x 2 x 19.5=122.460 m^2
now 
cost of constructing path =122.46 x 25
3061.5 Rs