SOLUTION: A motorboat can go 12 miles downstream on a river in 20 minutes. It takes 30 minutes for this boat to go back upstream the same 12 miles. Whats the speed of the boat in still water
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Question 750129: A motorboat can go 12 miles downstream on a river in 20 minutes. It takes 30 minutes for this boat to go back upstream the same 12 miles. Whats the speed of the boat in still water? Answer by stanbon(75887) (Show Source):
You can put this solution on YOUR website! A motorboat can go 12 miles downstream on a river in 20 minutes.
It takes 30 minutes for this boat to go back upstream the same 12 miles.
Whats the speed of the boat in still water?
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Downstream DATA:
dist = 12 miles ; time = 1/3 hr ; rate = d/t = 36 mph
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Upstream DATA:
dist = 12 miles ; time = 1/2 hr ; rate = d/t = 24 mph
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Equation:
Downstream: b + c = 36 mph
Upsteam ::: b - c = 24 mph
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Solve for "b":
2b = 60 mph
b = 30 mph (speed of the boat in quiet water)
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Solve for "c":
2C = 12 mph
c = 6 mph (speed of the current)
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Cheers,
Stan H.
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