Subject: mathqa
Question: a boat takes 19 hours for travelling downstream from point a to point b and coming back to a point c which is at midway between a and b . if the velocity of the stream is 4 kmph and the speed of the boat in still water is 14 kmph , what is the distance between a and b ?
Option: 
A: 188 km
B: 127 km
C: 180 km
D: 178 km
Answer: C