A certain drink of type A is prepared by mixing 4 parts milk with 3 parts fruit juice. Another drink of type B is prepared by mixing 4 parts of fruit juice and 3 parts of milk. How many liters of fruit juice must be added to 42 liters of drink A to convert it to drink B?	Select the correct option
A) 7
B) 9
C) 12
D) 14
E) 18
In 42 liters of drink A, there are 24 liters of milk and 18 liters of juice.   With 24 liters of milk, we need a total of 32 liters of juice to make drink B.   We need to add 14 liters of juice.   The answer is 14.
<result>D</result>
A certain drink of type A is prepared by mixing 4 parts milk with 3 parts fruit juice. Another drink of type B is prepared by mixing 4 parts of fruit juice and 3 parts of milk. How many liters of fruit juice must be added to 42 liters of drink A to convert it to drink B?