Excluding stoppages, the average speed of a bus is 60 km/hr and including stoppages, the average speed of the bus is 15 km/hr. For how many minutes does the bus stop per hour? Choose the correct answer:	A) 22	B) 88	C) 77	D) 20	E) 45
In 1hr, the bus covers 60 km without stoppages and 15 km with stoppages.   Stoppage time = time take to travel (60 - 15) km i.e 45 km at 60 km/hr.   stoppage time = 45/60 hrs = 45 min.   Answer: 45
<result>E</result>
Excluding stoppages, the average speed of a bus is 60 km/hr and including stoppages, the average speed of the bus is 15 km/hr. For how many minutes does the bus stop per hour?