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? Choose the correct choice from the following.
A) 4:5
B) 9:11
C) 2:3
D) 4:7
E) 3:7
Strength of milk in the mixture = Quantity of milk/total quantity of mixture   strength of milk in the 1st mixture = 10/15   strength of the milk 2nd mixture = 20/24   The ratio of their strengths = 10/15 : 20/24 = 4:5   Answer is 9:11
<result>B</result>
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?