Excluding stoppages, the speed of a bus is 80 kmph and including stoppages, it is 60 kmph. For how many minutes does the bus stop per hour?  Choose the correct answer:
A) 12 min  B) 20 min  C) 25 min  D) 30 min  E) 15 min
Due to stoppages, it covers 20 km less.   Time taken to cover 20 km = (20/80 x 60) min = 15 min   Answer : 15 min
<result>E</result>
Excluding stoppages, the speed of a bus is 80 kmph and including stoppages, it is 60 kmph. For how many minutes does the bus stop per hour?