Two vessels X and Y of equal capacities contain mixtures of milk and water in the ratio 2 1 and 5 1 ...........

Explanation:

Assume there is 30 liters of the mixture in both the vessels.
In vessel X, milk = 20 liters and water = 10 liters
20% from X to Y, milk in Y = 25 + 4 = 29 liters
And water in Y = 5 + 2 = 7 liters
Thus, ratio = 29:7
Equal amount from vessel Y to vessel X -
milk in X = 16 + 29/3
= 77/3
water in X= 8 + 7/3
= 31/3
Hence, the ratio is 77 : 31