A mixture contains milk and water in the ratio 3:2. On adding 10 litters of water, the ratio of milk to water becomes 2:3. Total quantity of milk & water before adding water to it?	Choose the correct choice from the following choices.
A) 10 B) 30 C) 50 D) 20 E) 30

Rationale: "explanation : milk : water = 3 : 2 after adding 10 liters of water milk : water = 2 : 3 olny water patrs increase when mixture of water milk : wate = 3 : 2 = 2 * ( 3 : 2 ) = 6 : 4 after adding 10 liters of water milk : water = 2 : 3 = 3 * ( 2 : 3 ) = 6 : 9 milk parts always same short cut method : milk : water = 6 : 4 after adding 10 liters of water milk : water = 6 : 9 milk is same but water increse 10 liters then the water ratio is increse 5 parts 5 part - - - - - > 10 liters the quantity of milk in the original mixture is = 6 : 4 = 6 + 4 = 10 10 parts - - - - - > 20 liters ( answer is = 20 ) short cut method - 2 : for only milk problems milk : water 6 : 4 6 : 9 milk ratio same but water ratio 5 parts incress per 10 liters 5 part of ratio - - - - - - - > 10 liters 10 part of ratio - - - - - - > 20 liters answer : option d"
Answer: D