Given a math problem with context and a question and 5 answer choices, the task is to provide the correct answer choice based on the problem. You must choose one of the given answer choices by letter: a, b, c, d, or e; anything else is invalid.
--------
Question: Problem: the total age of a and b is 15 years more than the total age of b and c. c is how many year younger than
Options: a. 14 years, b. 12 years, c. 56 years, d. 66 years, e. 15 years

Answer: e

Question: Problem: the overall age of x and y is 19 year greater than the overall age of y and z. z is how many decades younger that x ?
Options: a. 11, b. 15, c. 12, d. 19, e. 20

Answer: d

Question: Problem: how many liters of water must be added to 18 liters of milk and water containing 10 % water to make it 70 % water ?
Options: a. 28, b. 32, c. 36, d. 40, e. 44

Answer:
c