Answer : Option B.
This is the question of removal and replacement If a vessel contains "x" litres of liquid A and if "y" litres be withdrawn and replaced by liquid B, then if "y" litres of the mixture be withdrawn and replaced by liquid B again, and the operation is repeated "n" times in all, then:
So, in the given question, we have A as wine and B as water and 2 operations have occurred.
Therefore, quantity of wine after 2 operations
Thus, in a mixture of 100 ltr, 81 is wine, so water will be 100 - 81 = 19 ltr
Required ratio of wine and water is 81 : 19