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: a man traveled from the village to the post - office at the rate of 25 kmph and walked back at the rate of 4 kmph. if the whole journey took 5 hours 48 minutes, find the distance of the post - office from the village ?
Options: a. 70 m, b. 80 km, c. 20 km, d. 10 km, e. 73 km

A: c
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Q: Problem: car x began traveling at an average speed of 35 miles per hour. after 72 minutes, car y began traveling at an average speed of 49 miles per hour. when both cars had traveled the same distance, both cars stopped. how many miles did car x travel from the time car y began traveling until both cars stopped ?
Options: a. 105, b. 120, c. 140, d. 147, e. 168

A: a
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Q: Problem: 90 + 5 * 12 / ( 180 / 3 ) = ?
Options: a. 23, b. 78, c. 27, d. 91, e. 81

A:
d
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