Task: Question Answering
Input (English): Problem: a cistern can be filled by a tap in 5 hours while it can be emptied by another tap in 10 hours . if both the taps are opened simultaneously then after how much time will the cistern get filled ? 
Options: a ) 20 hr , b ) 10 hr , c ) 5 hr , d ) 4 hr , e ) 15 hr
Output (English): b