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: how many prime numbers are between 29 / 3 and 87 / 6 ?
Options: a. 1, b. 2, c. 3, d. 4, e. 5

SOLUTION: b

PROBLEM: Problem: a train of length 250 m crosses a bridge of length 150 m in 20 seconds. what is the speed of train ?
Options: a. 33, b. 27, c. 25, d. 22, e. 72

SOLUTION: e

PROBLEM: Problem: if the side of the regular hexagon above is 2, what is the circumference of the inscribed circle ?
Options: ['a. 2 ∏ √ 3', 'b. 3 ∏', 'c. 4 ∏ / √ 3', 'd. 2 ∏ / √ 3', 'e. ∏ √ 3']

SOLUTION:
a