Question

A road 3.5m wide surrounds a circular plot whose circumference is 44m. Find the cost of having the road at rupe 20 per m 2. (Take 22/7)

Answer 1

60,845.6 is the answer

Answer 2

to find the radius of the circle

2πR=44
22/7*r=44/2
r=77/22
r=7/2
r=3.5m

radius of road + radius of circular plot
=44+3.5=47.5m

total area=π r^2
=22/7*47.5*47.5=7,091.07m^2. [1]

radius of circular plot=44m
=area of the plot=π r^2
22/7*44*44=6,084.57m^2 [2]

from[1] &[2]
total area - area of the plot=7,091.07 - 6,084.57
=1,006.5m^2
total cost of making road=1,006.5*20= Rs 20,130