Excluding stoppages, the speed of a train is 45 kmph and including stoppages it is 42 kmph. Of how many minutes does the train stop per hour?	Choose the correct choice from the following answers.
A) 16  B) 4  C) 15  D) 18  E) 12

Rationale: "t = 3 / 45 * 60 = 4 answer : b"
Answer: B