Task: Question Answering
Input (English): Problem: one pipe can fill a tank three times as fast as another pipe . if together the two pipes can fill the tank in 39 minutes , then the slower pipe alone will be able to fill the tank in 
Options: a ) 144 mins , b ) 140 mins , c ) 136 mins , d ) 156 minw , e ) none of these
Output (English): d