In a 75 liters of mixture of milk and water, 20% of mixture is water. The milkman sells 25 liters of mixture and mixes equal quantity of water. What is the ratio of milk and water in the final mixture?

Initially, the mixture has 20% water, so 75 liters contains 15 liters water and 60 liters milk (ratio 4:1). When 25 liters is removed, the proportional removal leaves 36 liters milk and 9 liters water. Adding 25 liters water changes the mixture to 36 liters milk and 34 liters water, giving a ratio of 36:34 or 18:17, which is not among the given options.