SOLUTION: David's boat can travel 11 miles downstream in the same amount of time it can travel 9 miles upstream. If the speed of the boat is 20 miles per hour in still water, find the speed

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Question 32149: David's boat can travel 11 miles downstream in the same amount of time it can travel 9 miles upstream. If the speed of the boat is 20 miles per hour in still water, find the speed of the current.
Answer by Paul(988) About Me  (Show Source):
You can put this solution on YOUR website!
Let the speed of the current be x:;
equation:
11(20-x)=9(20+x)
220-11x=180+9x
40=20x
x=2
Hence, the speed of the current is 2mph.
PAul.