Question

A fish can swim 45 miles downriver in the same amount of time that it can swim 27 miles upriver. Solve for the speed of the current if the speed of the fish is 12 mph in still water. Show all of your work and explain your solution.

Answer 1

downstream speed = (v+c)
upstream speed = (v-c)
time = t

(v+c)t = 45
(v-c)t = 27

(12+c)t = 45
(12-c)t = 27
so
45/(12+c) = 27/(12-c)
45 (12-c) = 27 (12+c)
etc