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.
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Question: Problem: last year elaine spent 20 % of her annual earnings on rent. this year she earned 20 % more than last year and she spent 30 % of her annual earnings on rent. the amount she spent on rent this year is what percent of the amount spent on rent last year ?
Options: a. 185.5, b. 180.0, c. 167.5, d. 172.5, e. 177.5

Answer: b

Question: Problem: the salary of a person was reduced by 14 %. by what percent should his reduced salary be raised so as to bring it at par with his original salary ?
Options: a. 10 %, b. 16.3 %, c. 13.7 %, d. 15.1 %, e. 12.3 %

Answer: b

Question: Problem: a student chose a number, multiplied it by 2, then subtracted 138 from the result and got 112. what was the number he chose ?
Options: a. 123, b. 267, c. 125, d. 267, e. 120

Answer:
c