A steamer going downstream traveled the distance between two ports in 3 hours. The return trip took 3 hours 40 minutes. Find the speed of the water current if the speed of the steamer in still water is 18 mph.
distance = D
return trip time (RT) = 3 hours 40 minutes.
speed of the water current = VW
steamer speed (SS) = 18 mph
direct trip time (DT) = 3 hours
D = DT x (18 + VW) = 3(18 + VW) = 54 + 3VW
D = RT x (18 -VW) = 3.666 x (18 - VW) = 66 - 3.666VW
54 + 3VW = 66 - 3.666VW
3VW + 3.666VW = 66 - 54
6.666VW = 12
VW = 1. 8 mph