One man adds 5 liters of water to 10 liters of milk and another 4 liters of water to 20 liters of milk. What is the ratio of the strengths of milk in 2 mixtures?
Pick one.
A) 4 : 5
B) 9 : 11
C) 2 : 3
D) 4 : 7
E) 3 : 7

Rationale: strength of milk in the mixture = quantity of milk / total quantity of mixture strength of milk in the 1 st mixture = 10 / 15 strength of the milk 2 nd mixture = 20 / 24 the ratio of their strengths = 10 / 15 : 20 / 24 = 4 : 5 answer is b
Answer: B