Answer- The above question is from the chapter 'Areas Related to Circles'.

Concepts used: 1) Circumference of circle = Total cost of fencing ÷ Cost per metre

2) Area of circle = πr²

3) Cost of cultivating field = Area of circle × Cost per m²

Given question: The cost of fencing around a circular field at ₹ 5 per m is ₹ 220. What is the total cost of cultivating the field at ₹ 10 per m² ?

Solution: Circumference of circle = Total cost of fencing ÷ Cost per metre

2πr = ₹220 ÷ ₹5

2πr = 44

× r = 22

r = 7 m

Area of circular field = πr² = × 7 × 7 = 154 m²

Cost of cultivating per m² = ₹10

Cost of cultivating 154 m² = 154 × 10 = ₹1540

∴ Cost of cultivating the field = ₹1540.