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.

[EX Q]: Problem: at 15: 00 there were 22 students in the computer lab. at 15: 03 and every three minutes after that, 3 students entered the lab. if at 15: 10 and every ten minutes after that 8 students left the lab, how many students were in the computer lab at 15: 44 ?
Options: a. 7, b. 14, c. 25, d. 27, e. 32
[EX A]: e

[EX 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
[EX A]: c

[EX Q]: Problem: a, b, c can complete a piece of work in 25, 5,10 days. working together, they complete the same work in how many days ?
Options: a. 2, b. 4 / 5, c. 50 / 17, d. 10, e. 24 / 7
[EX A]:
c