SOLUTION: A boat can travel on a river 7 miles upstream in the same time it takes to travel 9 miles downstream. Find the speed of the current if the speed of the boat in still water is 8 mil
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Question 10618: A boat can travel on a river 7 miles upstream in the same time it takes to travel 9 miles downstream. Find the speed of the current if the speed of the boat in still water is 8 miles per hour. Answer by mathmaven53(29) (Show Source):
You can put this solution on YOUR website! Let v be speed of current
Upstream the speed of the boat is 8-v
Since boat travels 7 miles upstream it does it in time 7/(8-v)
Downstream the speed of the boat is 8+v
It travels 9 miles in time 9/(8+v)
These times are equal
7/(8-v) = 9/(8+v)
Solving for v gives v=1 miles per hour