Question

Cost of fencing a circular field at the rate of Rs 24 per metre is Rs 5280.The field is need to be ploughed at the rate of Rs 0.50 per metre square. Find the cost of ploughing the field.

Answer 1

Length of the fence (in metres) = Total cost / Rate = 5280/24 = 220

So, circumference of the field = 220 m

Therefore, if r metres is the radius of the field, then

2πr = 220

or, 2 × 22/7× r = 220

or, r = (220 × 7)/(2 × 22) = 35

i.e., radius of the field is 35 m.

Therefore, area of the field = πr2 = 22/7 × 35 × 35 m2 = 22 × 5 × 35 m2

Now, cost of ploughing 1 m2 of the field = Rs 0.50

So, total cost of ploughing the field = Rs 22 × 5 × 35 × 0.50 = Rs 1925

Answer 2

Answer:

Step-by-step explanation:

1 m of fencing costs Rs. 24.

Hence for Rs. 5280, the length of fencing = 5280/24

= 220 m

 Circumference of the field = 220 m

∴ 2πr = 220

2 ×22/7 × r = 220

r =220 * 7/44

r=35m

Area of the field = πr2 = π(35)2 = 1225π m2

Cost of ploughing = Rs. 0.50 per m2

Total cost of ploughing the field = Rs. 1225π × 0.50 =

1225*22*1/7*2 =

Rs. 1925



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