posted by Meshelle on .
A Coast-Guard patrol boat travels 4 hr on a trip downstream with a 6-mph current. The return trip against the same current
takes 5 hr. Find the speed of the boat in still water
The downstream speed with respect to land is V+6 and the upstream speed is V-6, where V is the speed in still water.
Let the distance be D
D/(V+6) = 4 hrs
D/(V-6) = 5
4(V+6) = 5(V-6)
V = 54 mph