Question

A field is in the form of circle. A fence is to be erected around the field. The cost of fencing would to Rs. 2640 at rate of Rs.12 per metre. Then the field is to be thoroughs ploughed at cost of Rs. 0.50 per m². What is amount required to plough the field?

Answer 1

Total cost of fencing the circular field = Rs. 2640

Cost per metre fencing = Rs 12

Total cost of fencing = circumference x cost per fencing

⇒ 2640 = circumference x 12

⇒ circumference = 2640/12=220m

Let radius of field be r m

Circumference = 2πr m

2πr = 220

2 x 22/7 x r = 220

r = 70/2=35m

Area of field = πr²

= 22/7x35x35

= 3850 m².

Cost of ploughing per m² land = Rs. 0.50

Cost of ploughing 3850 m² land = 1/2 x 3850

= Rs. 1925.