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.

Input: Consider Input: Problem: a train 50 m long takes 6 sec to cross a man walking at 5 kmph in a direction opposite to that of the train. find the speed of the train ?
Options: a. 15 kmph, b. 25 kmph, c. 35 kmph, d. 45 kmph, e. 55 kmph

Output: b


Input: Consider Input: Problem: an aeroplane covers a certain distance at a speed of 150 kmph in 2 hours. to cover the same distance in 1 2 / 3 hours, it must travel at a speed of :
Options: a. 1300 kmph, b. 160 kmph, c. 180 kmph, d. 1080 kmph, e. none

Output: c


Input: Consider Input: Problem: the positive value of x that satisfies the equation ( 3 + 2 x ) ^ 5 = ( 1 + 3 x ) ^ 4 is between bunuel, can you please explain this one ?
Options: a. 0 and 0.5, b. 0.5 and 1, c. 1 and 1.5, d. 1.5 and 2, e. 2 and 2.5


Output: d