Excluding stoppages, the speed of a train is 42 kmph and including stoppages it is 27 kmph. Of how many minutes does the train stop per hour?
Choose the correct choice:
A) A)19.42
B) B)20.42
C) C)21.42
D) D)22.42
E) E)23.42
Explanation:   T = 15/42 * 60 = 21.42   Answer: Option 21.42
<result>C</result>
Excluding stoppages, the speed of a train is 42 kmph and including stoppages it is 27 kmph. Of how many minutes does the train stop per hour?