SOLUTION: A boat can travel at 10 mph in still water. It travels 75 miles downstream with the current in the same time it travels 25 miles upstream. What is the speed of the current?

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Question 129450: A boat can travel at 10 mph in still water. It travels 75 miles downstream with the current in the same time it travels 25 miles upstream. What is the speed of the current?
Answer by scott8148(6628) About Me  (Show Source):
You can put this solution on YOUR website!
let x=current __ time equals distance divided by rate

"It travels 75 miles downstream with the current" __ 75/(10+x)

"in the same time" __ =

"it travels 25 miles upstream" __ 25/(10-x)

75%2F%2810%2Bx%29=25%2F%2810-x%29

dividing by 25 and "cross" multiplying __ 3(10-x)=1(10+x) __ 30-3x=10+x __ 20=4x