120 liters of a mixture contains milk and water in the ratio 4:2. If 10 liters of this mixture be replaced by 10 liters of milk, the ratio of milk to water in the new mixture would be?  Pick.
A) 8 : 6	B) 9 : 3	C) 9 : 4	D) 9 : 6	E) 8 : 2

Rationale: quantity of milk in 120 liters if mix = 120 * 4 / 6 = 80 liters quantity of milk in 130 liters of new mix = 80 + 10 = 90 liters quantity of water in it = 130 - 90 = 40 liters ratio of milk and water in new mix = 90 : 40 = 9 : 4 answer is c
Answer: C