SOLUTION: Maricris rides her power boat up and down the Agno river. The water in the river flows at 6 miles per hour. Maricris takes 5 hours longer to travel 360 miles against the current th
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Question 1045497: Maricris rides her power boat up and down the Agno river. The water in the river flows at 6 miles per hour. Maricris takes 5 hours longer to travel 360 miles against the current than she does to travel 360 miles along with the current. What is the speed of Maricris boat in still water? Found 2 solutions by stanbon, MathTherapy:Answer by stanbon(75887) (Show Source):
You can put this solution on YOUR website! Maricris rides her power boat up and down the Agno river. The water in the river flows at 6 miles per hour. Maricris takes 5 hours longer to travel 360 miles against the current than she does to travel 360 miles along with the current. What is the speed of Maricris boat in still water?
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Upstream DATA:
dist = 360 miles ; time = x+5 hrs ; rate = d/t = 360/(x+5) mph
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Downstream DATA:
dist = 360 miles ; time = x hrs ; rate = 360/x mph
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Equation:
rate - rate = 6 mph
360/x - 360/(x+5) = 6
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360x + 360*5 - 360x = 6x(x+5)
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6x^2 + 30x - 5*360 = 0
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x^2 + 5x - 300 = 0
(x+20)(x-15) = 0
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Positive solution:
x = 15 hrs
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rate upstream = 360/(x+5) = 360/20 = 18 mph
rate downstream = 360/x = 360/15 = 24 mph
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Equation:
boat speed + current = 24 mph
b + 6 = 24
b = 18 mph (boat speed in calm water)
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Cheers,
Stan H.
You can put this solution on YOUR website!
Maricris rides her power boat up and down the Agno river. The water in the river flows at 6 miles per hour. Maricris takes 5 hours longer to travel 360 miles against the current than she does to travel 360 miles along with the current. What is the speed of Maricris boat in still water?
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