Joe takes twice as long as to row against a current as with it. If he rows 6 miles an hour in still water, what is the rate of the water?
speed of current ---- x mph
distance traveled each way ---- d miles
time with the current = d/(6+x)
time against the current = d/(6-x)
d/(6-x) = 2d/(6+x)
divide by d
1/(6-x) = 2(6+x)
6+x = 12 - 2x
3x = 6
x = 2
state your conclusion.