Task: Question Answering
Input (English): Problem: excluding stoppages , the average speed of a bus is 120 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 ? 
Options: a ) 15 min , b ) 18 min , c ) 16 min , d ) 20 min , e ) 40 min
Output (English): e