A mixture of 80 liters contain milk and water in the ratio of 4:1. 20 liters of mixture is taken out and 12 liters of milk is added. Again 24 liters of mixture is taken out and 12 liters of water is added. Find the ratio of milk to water in the final mixture.

Initial mixture: 80L with milk:water = 4:1, so milk = 64L, water = 16L. First removal: 20L taken out (maintaining 4:1 ratio), so 16L milk + 4L water removed. Remaining: 48L milk, 12L water. Add 12L milk: 60L milk, 12L water. Second removal: 24L taken out (ratio 5:1), so 20L milk + 4L water removed. Remaining: 40L milk, 8L water. Add 12L water: 40L milk, 20L water. Final ratio = 40:20 = 2:1. Option D is correct.