Question

A 7 m wide road runs around circular car whose circumference is 176 m find the cost of fencing the outer boundary of the road at the rate of ruppes 70 per m

Answer 1

let inner radius = R
2×pi×r = C
2(22÷7)×r = 176
r = ( 176 ×7 ÷(2×22)
r= 28 m
Let outer radius R
R = 28 + 7 = 35 m

outer boundary = 2 × Pi × R
= 2 × (22 ÷7) × 35
= 220m
total cost =220 × 70 = Rs 1540