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.

[Q]: Problem: a train 100 meters long completely crosses a 300 meters long bridge in 36 seconds. what is the speed of the train is ?
Options: a. 32 kmph, b. 76 kmph, c. 34 kmph, d. 43 kmph, e. 40 kmph
[A]: e


[Q]: 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
[A]: e


[Q]: Problem: a man can row downstream at 25 kmph and upstream at 15 kmph. find the time to reach a destination point at a distance of 50 km along the downstream.
Options: a. 4 hrs., b. 1 hrs., c. 3 hrs., d. 2 hrs., e. 2 1 / 2 hrs.
[A]:
d