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: if y exceeds x by 25 %, then x is less than y by ?
Options: a. 28 %, b. 21 %, c. 20 %, d. 30 %, e. 29 %

A: c
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Q: Problem: if a / b = 4 / 3, then ( 3 a + 2 b. / ( 3 a - 2 b. = ?
Options: a. 6, b. 3, c. 5, d. - 1, e. none

A: b
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Q: Problem: in what ratio mental a at rs. 68 per kg be mixed with another metal at rs. 96 per kg so that cost of alloy ( mixture. is rs. 80 per kg ?
Options: a. 5: 8, b. 4: 7, c. 4: 3, d. 9: 5, e. 9: 8

A:
c
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