Task: Question Answering
Input (English): Problem: excluding stoppages , the average speed of a bus is 60 km / hr and including stoppages , the average speed of the bus is 20 km / hr . for how many minutes does the bus stop per hour ? 
Options: a ) 22 , b ) 88 , c ) 77 , d ) 40 , e ) 99
Output (English): d