Question

A path of 4 m width runs round a semi-circular grassy plot whose circumference is 163
3/7
m Find:
(b) the area of the path
(ii) the cost of gravelling the path at the rate of 1.50 per square metre
(ii) the cost of turfing the plot at the rate of 45 paise per m.​

Answer 1

Answer:

Circumference of plot=163

7

3

m=

7

1144

m

⇒2πr=

7

1144

⇒r=

7×44

1144×7

=26m

i) Area of path=π(R

2

−r

2

)

=

7

22

((26+4)

2

−(26)

2

)

=

7

22

×14.97=47.05㎡

ii) Cost of graveling=Rs. (47.05×1.50)=Rs. 70.575

iii) Area of plot=πr

2

=

7

22

×26×26=2124.57㎡

Cost of turfing=Rs. (2124.57×0.45)=Rs. 956.06