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.

Q: 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

A: d
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Q: Problem: 11 is subtracted from 40 % of a number and results is 23. what is the number ?
Options: a. 160, b. 92, c. 88, d. 85, e. 34

A: d
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Q: Problem: the total age of a and b is 14 years more than the total age of b and c. c is how many years younger than a ?
Options: a. 14, b. 27, c. 21, d. 18, e. 11

A:
a
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