Excluding stoppages, the average speed of a bus is 100 km/hr and including stoppages, the average speed of the bus is 40 km/hr. For how many minutes does the bus stop per hour?  Choose the correct choice from the following choices
A) 15 min
B) 18 min
C) 16 min
D) 20 min
E) 36 min
In 1hr, the bus covers 100 km without stoppages and 40 km with stoppages.   Stoppage time = time take to travel (100 - 40) km i.e 60 km at 100 km/hr.   stoppage time = 60/100 hrs   = 36 min   Answer: 36 min
<result>E</result>
Excluding stoppages, the average speed of a bus is 100 km/hr and including stoppages, the average speed of the bus is 40 km/hr. For how many minutes does the bus stop per hour?