Question

Pure milk costs Rs. 3.60 per litre. A milkman adds water to 25 litres of pure milk and sells the mixture at Rs. 3 per litre. How much water does he add?
1. 5 L
2. 3 L
3. 2 L
4. 7 L
5. None

Answer 1

Correct Answer - Option 1 : 5 L

Given:

Cost of pure milk = Rs. 3.60/L

Selling price 1L milk mixed with water = Rs. 3

Concept used:

(Quantity of pure milk)/(Quantity of water) = (SP of mixture – 0)/(CP of milk – SP of mixture)

Calculation:

⇒ (Quantity of pure milk)/(Quantity of water)

⇒ (3 – 0)/(3.6 – 3)

⇒ 3/0.6

⇒ 5/1

⇒ Since in every 5 litres of milk, he adds 1 litre of water.

⇒  In every 25 litres of milk, he adds 5 litres of water.

∴ The required answer is 5 litres.