Question

A mixture contains 25% milk and rest water. what percent of this mixture must taken out and replaced with milk so that in mixture milk and water may become equal.

Answer 1

Let us assume that total amount of the mixture = 100 l

Milk is 25% and Water is 75% => Initial ratio is 25: 75 = 1 : 3

Total parts = 1+3 = 4

Milk = 25 l ; Water = 75 l

New ratio of milk to water in mixture is 50 : 50 = 1 : 1

Let x liter of mixture is drawn out and x liter of milk is added.

In new mixture, amount of milk will be: x + 25 - x/4

In new mixture, amount of water will be: 75 - 3x/4

new ratio = (x + 25 - x/4) / (75 - 3x/4) = 1

(x + 25 - x/4 = (75 - 3x/4)

x (1 - 1/4 - 3/4) = 75-25

6x = 50 * 4

x = 100/3 = 33.3

Out of 100l , 33.3l is 33.3%

So, to make the water and milk quantity equal in the mixture, 33.3% of mixture must be replaced by milk.