instruction:
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.
question:
Problem: if x + y = 260, x - y = 200, for integers of x and y, y = ?
Options: a. 200, b. 230, c. 50, d. 115, e. 150
answer:
b

question:
Problem: the average age of 15 students of a class is 15 years. out of these, the average age of 8 students is 14 years and that of the other 6 students is 16 years, the age of the 15 th student is
Options: a. 17, b. 12, c. 13, d. 14, e. 15
answer:
a

question:
Problem: what is the units digit of 32 ! + 50 ! + 4 ! + 4 ! ?
Options: a. 0, b. 2, c. 4, d. 6, e. 8
answer:
e