14. A field is in the form of a circle. The cost ofploughing the field

1.	14. A field is in the form of a circle. The cost ofploughing the field at R 15 per m^2 is Rs 57,750.Find the cost of fencing the field at 34 permetre
Answer» Area ploughed for Rs. 15 = 1 m2 Area ploughed for Rs. 57750 = (1/15) × 57750= 3850 m2 area of circular field = 3850 m2 let r be the radius of the field. so, π r2= 3850 ⇒ r2= 3850 / π = (3850×7) / 22 = 1225 so, r = 35 m perimeter of field = 2 π r = 2 × 22/7 × 35 = 220 m so, total cost of fencing = 34 × 220 = Rs. 7480

14. A field is in the form of a circle. The cost ofploughing the field at R 15 per m^2 is Rs 57,750.Find the cost of fencing the field at 34 permetre

Answer»

Area ploughed for Rs. 15 = 1 m2

Area ploughed for Rs. 57750 = (1/15) × 57750= 3850 m2

area of circular field = 3850 m2

let r be the radius of the field.

so, π r2= 3850 ⇒ r2= 3850 / π = (3850×7) / 22 = 1225

so, r = 35 m

perimeter of field = 2 π r = 2 × 22/7 × 35 = 220 m

so, total cost of fencing = 34 × 220 = Rs. 7480