Question

A vessel contains 60 liters of a mixture of milk and water in which there is 10% water. What should be the quantity of water to be added to the mixture to make 40% water?
1. 10 liters
2. 15 liters
3. 30 liters
4. 40 liters

Answer 1

Correct Answer - Option 3 : 30 liters

Given:

The total quantity of mixture = 60 liters

Percentage of water in the mixture = 10%

Calculation:

Let the added quantity of water be x

According to the question, we have,

The quantity of water in the original mixture,

⇒ 60 × 10%

⇒ 60 × (10/100)

⇒ 6 liters

After adding x liters of water, the new quantity of water = x + 6

And the total quantity of mixture will become = x + 60

According to the question,

New amount of water in the mixture is 40%

So, {(x + 6)/(x + 60)} × 100 = 40

⇒ {(x + 6)/(x + 60)} = 2/5

⇒ 5x + 30 = 2x + 120

⇒ 3x = 90

⇒ x = 30 litres

∴ The added quantity of the water is 30 litres.