Question

The diameter of a circular park is 140m.Around it on the outside, a path having the width of 7m is constructed. If the path has to be fenced from inside and outside at the rate of ₹7 per metre,find its total cost.

Answer 1

1.Cost of fence from inside:
Circumference=
$\pi \times d$
Therefore 22/7 *140
=440 m
Therefore., cost =440*7
=rs. 3080
2. Cost of fence from outside
$circumference = \pi \times d$
Therefore, 22/7*(140+7)


=462
Therefore, cost =462*7
=Rs. 3234
Therefore total cost= 3234 +3080
=Rs.6314

Answer 2

We have to find the inside distance and outside distance.

for inside distance, radius = 140/2 = 70 m

length of circumference = 2Π × radius

= 2 × (22/7) × 70

= 440 m

now, outside distance radius = 70 + 7 = 77 m

length of circumference = 2Π × radius

= 2 × (22/7) × 77

= 484 m

total length = 440 + 484 = 924 m

cost = Rs 7 × 924 = Rs 6468