The cost of cultivating a square field at the rate of ₹ 160 per hectare is ₹ 1,440. Find the cost of putting a fence around it at the rate of 75 paise per metre.

Given,

Rate of cultivation = ₹ 160 per hectare

Total cost = ₹ 1,440

Area of cultivation = $\dfrac{\text{Total cost}}{\text{Rate}}$

= $\dfrac{1440}{160}$ = 9 hectares.

1 hectare = 10,000 m²

9 hectares = 9 × 10,000 = 90,000 m².

Area of square = (side)²

90,000 = (side)²

Side = $\sqrt{90,000}$

Side = 300 m.

Perimeter of square = 4 × side

= 4 × 300 = 1200 m

Total cost = Perimeter × Fencing rate

= 1200 × ₹ 0.75

= ₹ 900.

Hence, cost of fencing around the square field = ₹ 900.