TASK DEFINITION: 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.
PROBLEM: Problem: what is the units digit of ( 3 ^ 13 ) ( 4 ^ 13 ) ?
Options: a. 2, b. 4, c. 6, d. 7, e. 8

SOLUTION: a

PROBLEM: Problem: the l. c. m of two numbers is 495 and their h. c. f is 5. if the sum of the numbers is 100, then their difference is
Options: a. 19, b. 10, c. 28, d. 27, e. 29

SOLUTION: b

PROBLEM: Problem: two trains, a and b, started simultaneously from opposite ends of a 125 - mile route and traveled toward each other on parallel tracks. train a, traveling at a constant rate, completed the 125 - mile trip in 12 hours; train b, traveling at a constant rate, completed the 125 - mile trip in 8 hours. how many miles had train a traveled when it met train b ?
Options: a. 25, b. 37.5, c. 40, d. 45.5, e. 50

SOLUTION:
e