Question

The cost of fencing a circular field at the rate of Rs 25 per metre is Rs 5500. The field is to be ploughed at the rate of 50 paise per m² . Find the cost of ploughing the field. [Take `π =22/7`].

Answer 1

Circumference`=("Total cost of fencing")/("Rate of fencing") = 5500/25 = 220`

Let the radius of the circle be r.

Now,

Circumference = 220

⇒ 2πr  = 220

⇒ r = 35 cm

Now,

Area of field=`pi"r"^2 = 22/7xx(35)^2= 3850  "cm"`

Cost of ploughing = Rate ⨯ Area of field = 0.5 3850 = Rs 1925

Hence, the cost of ploughing the field is Rs 1925.