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: what is the smallest number which, when increased by 7, is divisible by 8, 11, and 24 ?
Options: a. 264, b. 257, c. 269, d. 270, e. 282
answer:
b

question:
Problem: if 7 a = 8 b and ab = 0, what is the ratio of a / 8 to b / 7 ?
Options: a. 16 / 14, b. 8 / 7, c. 1, d. 7 / 8, e. 64 / 49
answer:
c

question:
Problem: a man sold 20 articles for $ 60 and gained 20 %. how many articles should he sell for $ 40 to incur a loss 20 % ?
Options: a. 20, b. 36, c. 40, d. 50, e. 48
answer:
a