Question 565329
boat rate in still water = 5mph

upstream rate = 5-x
downstream rate = 5+x

time upstream = 1/4 hour
time downstream = 1/6 hour

Distance up and down is the same

d=rt
(5-x)*1/4 = (5+x)*1/6

multiply the equation by 12
3(5-x)=2(5+x)
15-3x=10+2x
5x=5

x=1 mph speed of current

D= (5-1)*1/4 = 1 mile