A milk vendor sells milk at Cost Price but still gains 20%. Find the ratio of milk and water in every gallon that he sells?
assume that initially he has 100gallons of milk that costs 100 USD @ USD 1 per gallon
To earn 20 % profit, he must earn USD 120, by selling the same qty of milk
But the selling price of milk = the cost price of the milk.
qty of milk and water mixture sold = 120/1 = 120 gallons
of the 120 lgallons, 100gallons are milk so the remaining must be water added.
Thus the amount of water added = 20 gallons
ratio of milk :water = 100:20 = 5:1
