Task: Question Answering
Input (English): Problem: a cistern can be filled by a tap in 3 hours while it can be emptied by another tap in 5 hours . if both the taps are opened simultaneously , then after how much time will the cistern get filled ? 
Options: a ) 5.2 hrs , b ) 2.9 hrs , c ) 1.9 hrs , d ) 7.5 hrs , e ) 1.4 hrs
Output (English): d