How much water (in ml) should be added to 300 ml of a 75% milk and water mixture so that it becomes a 45% milk and water mixture?

200

Initial Solution,

Milk : Water

 3    :   1,

Final solution after adding some quantity of water, 

Milk : Water

 9    :   11,

Making ratio of Milk in both solution same, we multiply initial solution with 3,

⇒ (3 : 1) x 3 = 9 : 3,

⇒ Quantity of Initial solution = 300 ml

⇒ (9 + 3)x = 300,

⇒ 12x = 300,

⇒ x = 25 ml,

⇒ Initial solution,

Milk = 9 x 25 = 225 ml, Water = 3 x 25 = 75 ml,

⇒ Final Solution,

Milk = 9 x 25 = 225 ml, Water = 11 x 25 = 275 ml,

⇒ Amount of water added to initial solution = 275 - 75 = 200 ml