Question

Question 5 solution please

Answer 1

surface area of road = surface area of outer road - surface area of inner road
circumference of inner road= 2πr
440=2πr
220=πr
r=220*7/22
r= 10*7
r= 70m
now we have radius
surface area of inner road = πr2
= 22/7*70*70
=22*700
=15400
now area of outer road= π(r+10)2
=22/7*80*80
=20106
surface area of road = 20106-15400
= 4706 m2
cost of leveling

=4706*70₹
=₹329420