Task: Question Answering
Input (English): Problem: a person can swim in still water at 16 km / h . if the speed of water 8 km / h , how many hours will the man take to swim back against the current for 12 km ? 
Options: a ) 3 , b ) 1.5 , c ) 2.3 , d ) 1.8 , e ) 6
Output (English): b