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: if julie rows 32 km upstream and 72 km down steam taking 4 hours each, then the speed of the stream
Options: a. 1.5 kmph, b. 0.5 kmph, c. 0.4 kmph, d. 1.6 kmph, e. 2.5 kmph
[A]: b


[Q]: Problem: a man sitting in a train which is traveling at 36 kmph observes that a goods train, traveling in opposite direction, takes 10 seconds to pass him. if the goods train is 240 m long, find its speed
Options: a. 50 kmph, b. 56 kmph, c. 58 kmph, d. 62 kmph, e. 72 kmph
[A]: a


[Q]: Problem: a dog takes 5 leaps for every 7 leaps of a hare. if one leap of the dog is equal to 3 leaps of the hare, the ratio of the speed of the dog to that of the hare is :
Options: a. 16: 7, b. 15: 7, c. 20: 7, d. 7: 15, e. 14: 7
[A]:
b