SOLUTION: A boat can go 20 miles against a current in the same time that it can go 60 miles with the current. The current is 4 mph. Find the rate of the boat in still water.
speed time distance
AGAINST r-4 t 20
WITH r+4 t 60
Solve for r. Answer by stanbon(75887) (Show Source): You can put this solution on YOUR website! A boat can go 20 miles against a current in the same time that it can go 60 miles with the current. The current is 4 mph. Find the rate of the boat in still water.
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With Current DATA:
rate = b+4 mph ; time = t hrs ; distance 60 miles
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Against Current DATA:
rate = b-4 mph ; time = t hrs ; distance = 20 miles
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Equations:
bt + 4t = 60
bt - 4t = 20
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8t = 40
time = 5 hrs
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rate in still water ::
(b+4)5 = 60
b+4 = 12
Ans: boat = 8 mph
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Cheers,
Stan H.
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