Can anyone help me set up an equation for this problem please? Traveling at full speed on a river, it takes 2 hrs for a motorboat to travel 8 miles downstream and 4 miles back upstream. If the current's speed is 2 mph, what is the maximum speed of the boat in still water?

Question

dumbcow · Answer

Let s be boats speed.
d = r*t
8 = 2(s+2)
8 = 2s +4
s = 2
however that cannot be boats max speed or else it would never be able to get upstream
4 = 2(s-2)
4 = 2s-4
s = 4

max speed = 4 mph