A dairyman pays Rs. 6.4 per litre of milk. He adds water and sells the mixture…

2025

A dairyman pays Rs. 6.4 per litre of milk. He adds water and sells the mixture at Rs. 8 per litre, thereby making 37.5% profit. Find the proportion of the water to that of the milk received by the customers.

  1. A.

    3:10

  2. B.

    1:10

  3. C.

    1:15

  4. D.

    2:5

Attempted by 222 students.

Show answer & explanation

Correct answer: B

Given: Milk costs Rs. 6.4 per litre. The mixture is sold at Rs. 8 per litre with 37.5% profit.

  1. Profit 37.5% = 3/8, so Selling Price = (11/8) × Cost Price. Hence cost price per litre of mixture = 8 ÷ (11/8) = 64/11.

  2. Let the mixture contain m litres of milk in 1 litre of mixture. Water is free, so cost per litre of mixture = 6.4m.

  3. So 6.4m = 64/11 ⇒ m = (64/11)/6.4 = (64/11)/(64/10) = 10/11.

  4. Therefore water in 1 litre = 1 − 10/11 = 1/11. So water : milk = (1/11) : (10/11) = 1 : 10.

Explore the full course: Tcs Preparation