Question

In 90 litres mixture of milk and water, the ratio of the amount of milk to that of the amount of water is 5 ∶ 4. In order to make this ratio 1 ∶ 1. How many litres of water should be added?
1. 10 liters
2. 5 liters
3. 20 liters
4. 15 liters

Answer 1

Correct Answer - Option 1 : 10 liters

Given:

The total quantity of mixture = 90 litres

The ratio of milk to water is 5 ∶ 4

Calculation:

In 90 litres

Quantity of milk = 90 × (5/9) = 50 liters

Quantity of water = 90 × (4/9) = 40 liters 

Let x liters of water is added in the mixture to make the ratio of milk to water 1 ∶ 1

⇒ (50/(40 + x)) = 1/1

⇒ 50 = 40 + x

⇒ x = 50 - 40 = 10

∴ 10 liters of water should be added in the mixture.