Question

A vessel has 30 liters of a mixture of milk and water containing 80% milk. How many liters of water must be added to the vessel to reverse the ratio of milk and water.
1. 20
2. 90
3. 50
4. 40
5. None

Answer 1

Correct Answer - Option 2 : 90

Calculation:

Quantity of milk in 30 liters solution = 30 × 80/100 = 24 liters

∴ Quantity of water = 30 - 6 = 24 liters

Let the quantity of water to be added be x liters.

⇒ (6 + x)/(30 + x) = 80%/100%

⇒ (6 + x)/(30 + x) = 4/5

⇒ x = 90

∴ The required answer is 90 liters.