Excluding stoppages, the speed of a train is 60 kmph and including stoppages it is 40 kmph. Of how many minutes does the train stop per hour?
Choose the correct choice from the following answers:
A) 12	B) 14	C) 16	D) 18	E) 20

Rationale: "explanation : t = 20 / 60 * 60 = 20 answer : option e"
Answer: E