Question

How much water must be added to a tub which contains 30 liters of milk at a cost price of Rs. 20/liter so that the cost of milk reduces to Rs. 15/liter.

1. 20 liters
2. 10 liters
3. 15 liters
4. 12 liters
5. None of these

Answer 1

Correct Answer - Option 2 : 10 liters

 

Given:

Quantity of milk in the tub = 30 liters

The cost price of milk = 20/liter

The cost price of new mixture = 15/liter

Concept used:

The new price of milk = (Total cost price of the milk)/(New quantity of the mixture)

Calculation:

The total cost price of the milk = 20 × 30

⇒ 600

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

Then, 600/(30 + x) = 15

⇒ 600 = 450 + 15x

⇒ 15x = 150

⇒ x = 10

∴ The quantity of water added in the tub is 10 liters.