A swimmer can swim 1.7 mph in still water. She decides to swim upsteam against the current which is 0.7 mph. It will take the swimmer ___ hours to travel 8 miles as measured by a person standing on the river bank.
d = V*t = 8 miles
(Vs-Vc)t = 8
Vs = 1.7 m/h
Vc = 0.7 m/h
Solve for t.