Task: Question Answering
Input (English): Problem: a train is walking at 6 / 7 of its usual speed , the train is 20 minutes too late . find its usual time to cover the journey . 
Options: a ) 1 hour , b ) 30 min , c ) 3 hours 20 min , d ) 2 hours 30 min , e ) 2 hours
Output (English): e