The length and breadth of a rectangular field are 500 m and 300 m respectively. Find the cost of the grass to be planted in it at the rate of ₹ 2.50 per m².

Given,  Length = 500 m, Breadth = 300 m

Area of the field = l × b = 500 m × 300 m = 150000 m²

Cost of planting the grass in 1 m²  =  ₹ 2.50

Cost of planting the grass in 150000 m²  =  ₹ 2.50 × 150000 = ₹ 3,75,000

Hence, the required cost = ₹ 3,75,000.