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: two trains of length 100 meters and 200 meters are 450 meters apart. they are moving towards each other on parallel tracks, at speeds of 90 km / h and 72 km / h. after how many seconds will the trains meet ?
Options: a. 6, b. 8, c. 10, d. 12, e. 14

A: c
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Q: Problem: find the value o f 72519 x 9999 = m ?
Options: a. 434539873, b. 355797990, c. 435453490, d. m = 725117481, e. 873430134

A: d
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Q: Problem: the total price of a basic computer and printer are $ 2,500. if the same printer had been purchased with an enhanced computer whose price was $ 500 more than the price of the basic computer, then the price of the printer would have been 2 / 5 of that total. what was the price of the basic computer ?
Options: a. 1300, b. 1600, c. 1750, d. 1900, e. 2000

A:
a
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