A Boat covers upstream in 12 Hours 48 minutes to travel distance from Point A to B, while it takes 6 hours to cover 3/4th of the same distance running downstream. Then what is the distance between A and B?
S+R)*8 = (S-R)*64/5
S:R = 13:3
R = 15 (given)
S = 65
D = (65+15) *8 = 640