Profit = Selling Price (SP) - Cost Price (CP)
1) CP = ₹100, SP = ₹300
∴ Profit = 300 - 100 = ₹200
2) CP = ₹100, SP = ₹150
∴ Profit = 150 - 100 = ₹50
3) CP = ₹75, SP = ₹100
∴ Profit = 100 - 75 = ₹25
4) CP = ₹110, SP = ₹180
∴ Profit = 180 - 110 = ₹70
So, from the least profitable to the most profitable sale, the order will be
₹25 < ₹50 < ₹70 < ₹200