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: if the wages of 6 men for 15 days be rs. 2100, then find the wages of for 12 days.
Options: a. rs. 2420, b. rs. 2500, c. rs. 2520, d. rs. 2020, e. rs. 2650

Answer: c

Question: Problem: if 7 a = 8 b and ab = 0, what is the ratio of a / 8 to b / 7 ?
Options: a. 16 / 14, b. 8 / 7, c. 1, d. 7 / 8, e. 64 / 49

Answer: c

Question: Problem: the compound interest on $ 30,000 at 7 % p. a is $. 4347. find out the period ( in years ) ?
Options: a. 1, b. 1.5, c. 2, d. 2.5, e. 3

Answer:
c