SOLUTION: Juniors boat will go 15 miles per hour in still water. If he can go 12 miles downstream in the same amount of time as it takes to go 9 miles upstream, then what is the speed of the

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Question 397760: Juniors boat will go 15 miles per hour in still water. If he can go 12 miles downstream in the same amount of time as it takes to go 9 miles upstream, then what is the speed of the current.

Answer by lwsshak3(11628) About Me  (Show Source):
You can put this solution on YOUR website!
Juniors boat will go 15 miles per hour in still water. If he can go 12 miles downstream in the same amount of time as it takes to go 9 miles upstream, then what is the speed of the current.
let x = speed of current
15+x = speed of boat downstream
15-x = speed of boat upstream
distance/speed = time of travel
time of travel downstream=time of travel downstream
12/(15+x)=9/(15-x)
180-12x=135+9x
21x=45
x=21/45 mph
ans: the speed of the current is 21/45 miles per hour