Question

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

Answer 1

the total amount is 1925

Answer 2

Given,

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.