Correct Answer - Option 2 : 60

**Given **

Quantity of mixtures = 60 litres

**Calculation **

Ratio of milk and water = 2 : 1 (initially) ---(1)

Final ratio M : W = 1 : 2 ---(2)

We know the quantity of milk is same in both condition

So, eq(2) is multiply by 2

Final ratio M : W = 2 : 4

Total Quantity Initially = 60 litres

⇒ 3x = 60

⇒ x = 20

Change in water = 4x - x = 3x = 3 × 20 = 60 litres

**∴ The water added in mixture is 60 litres **