Question

The radius of a circular garden is 100 m. There is a road 10 m wide, running all around it. Find the area of the road and the cost of levelling it at Rs 20 per $m^2$. [ Use $\pi$ = 3.14]

Answer 1

The outer radius of path R= 100m
width of path = 10m
the inner radius of path r = 100-10 = 90m

Area of path = area of outer circle - area of the inner circle
$=\pi R^2-\pi r^2$
$=\pi \times {100}^2-\pi \times {90}^2$
$=423.115m^2$
Price at Rs.20 per $m^2$ = 5969.02$\times$20 = Rs. 119380.5