A sculling team leaves the boat launch an travels down river with the aid of a 3 mph current. After 3 hours they turn around travling against the same current and return to the boat launch in 5 hrs. At what rate, in still water, would the sculling team be averaging?

Solution:

                Let the speed of boat in still water = v mph

                  (v + 3) * 3 = (v - 3) * 5

                   2v = 9 + 15 = 24

                       v = 12 mph