Task: Question Answering
Input (English): Problem: a boat takes 19 hours for travelling downstream from point a to point b and coming back to a point c midway between a and b . if the velocity of the stream is 4 km / h and the speed of the boat in still water is 14 km / h , what is the distance between a and b ? 
Options: a ) 200 km , b ) 180 km , c ) 160 km , d ) 220 km , e ) none of these
Output (English): b