Excluding stoppages, the speed of a bus is 54 kmph and including stoppages, it is 45 kmph. For how many minutes does the bus stop per hour?	Choose the correct choice.
A) 9  B) 10  C) 12  D) 16  E) 20
Due to stoppages, it covers 9 km less.   Time taken to cover 9 km = 9/54	x 60	min	= 10 min.   Answer: 10
<result>B</result>
Excluding stoppages, the speed of a bus is 54 kmph and including stoppages, it is 45 kmph. For how many minutes does the bus stop per hour?