Question

In a mixture of 60 litres, the ratio of milk and water is 2 : 1. To make this ratio 1 : 2, what quantity of water (in litres) is to be added to the mixture ?
1. 30
2. 60
3. 90
4. 100

Answer 1

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