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: ages of two persons differ by 20 years. if 6 year ago, the elder one be 3 times as old the younger one, find their present age
Options: a. 12,28, b. 14,30, c. 16,36, d. 18,34, e. 19,34

Answer: c


Question: Problem: by selling 15 pencils for a rupee a man loses 20 %. how many for a rupee should he sell in order to gain 20 % ?
Options: a. 8, b. 7, c. 6, d. 4, e. 10

Answer: e


Question: Problem: a particular library has 75 books in a special collection, all of which were in the library at the beginning of the month. these book are occasionally loaned out through an inter - library program. if, by the end of the month, 80 percent of books that were loaned out are returned and there are 66 books in the special collection at that time, how many books of the special collection were loaned out during that month ?
Options: a. 20, b. 30, c. 35, d. 45, e. 55

Answer:
d