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: 4, 12, 48, 240, 1440, 10080,80640 (... )
Options: a. 7620, b. 10080, c. 6200, d. 10020, e. 725760
[A]: e


[Q]: Problem: a / ( b / c. in the expression above, a, b, and c are different numbers and each is one of the numbers 2, 3, or 6. what is the largest possible value of the expression ?
Options: a. 2 / 18, b. 6 / 3, c. 30 / 2, d. 18 / 2, e. 6 / 18
[A]: d


[Q]: Problem: two cyclist start on a circular track from a given point but in opposite direction with speeds of 7 m / s and 8 m / s. if the circumference of the circle is 630 meters, after what time will they meet at the starting point ?
Options: a. 20 sec, b. 15 sec, c. 42 sec, d. 50 sec, e. 1 min
[A]:
c