SOLUTION: The current of a river moves at 3 miles per hour. It takes a boat a total of 3 hours to travel 12 miles upstream, against the current, and return the same distance traveling downst
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Question 962688: The current of a river moves at 3 miles per hour. It takes a boat a total of 3 hours to travel 12 miles upstream, against the current, and return the same distance traveling downstream, with the current. What is the boat’s rate in still water? Answer by Murthy(22) (Show Source):
You can put this solution on YOUR website! Let 'x' be the speed of the boat in miles per hour in still water
During upstream relative speed of the boat will be (x-3) miles per hour
During downstream relative speed of the boat will be (x+3) miles per hour
total time = time taken (upstream)+ time taken (downstream)
3= distance/(upstream speed)+ distance/(dowmstream speed)
12/(x-3)+12/(x+3)=3
=x^2-8x-9=0
x=9 miles /hour
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