Task: Question Answering
Input (English): Problem: a cistern which could be filled in 9 hours takes one hour more to be filled owing to a leak in its bottom . if the cistern is full in what time will the leak empty it ? 
Options: a ) 76 hrs , b ) 99 hrs , c ) 55 hrs , d ) 90 hrs , e ) 11 hrs
Output (English): d