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 ? Choose the correct choice.
A) 180 km  B) 127 km  C) 178 km  D) 188 km  E) 111 km
Explanation:   Speed in downstream = (14 + 4) km/hr = 18 km/hr;   Speed in upstream = (14 â€“ 4) km/hr = 10 km/hr.   Let the distance between A and B be x km. Then,   x/18 + (x/2)/10 = 19 â‡” x/18 + x/20 = 19 â‡’ x = 180 km.   180 kmnswer: 180 km
<result>A</result>
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 ?