Excluding stoppages, the speed of a train is 48 kmph and including stoppages it is 36 kmph. Of how many minutes does the train stop per hour?	Choose the correct choice
A) 16	B) 17	C) 15	D) 18	E) 12

Rationale: "t = 12 / 48 * 60 = 15 answer : c"
Answer: C