The cost of fencing a circular field at the rate of Rs 24 per metre is Rs 5280. The field is to be ploughed at the rate of Rs 0.50 per m2.
The cost of fencing a circular field at the rate of Rs 24 per metre is Rs 5280. The field is to be ploughed at the rate of Rs 0.50 per m2. Find the cost of ploughing the field (Take pi = 22/7 ).
4 views
1 Answers
Solution : 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
4 views
Answered