SOLUTION: A plane flies 400 miles with the wind and 320 miles against the wind in the same lenght of time. If the speed of the wind is 24 mph, what is the speed of the plane in still air?
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-> SOLUTION: A plane flies 400 miles with the wind and 320 miles against the wind in the same lenght of time. If the speed of the wind is 24 mph, what is the speed of the plane in still air?
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Question 94226: A plane flies 400 miles with the wind and 320 miles against the wind in the same lenght of time. If the speed of the wind is 24 mph, what is the speed of the plane in still air? Answer by stanbon(75887) (Show Source):
You can put this solution on YOUR website! A plane flies 400 miles with the wind and 320 miles against the wind in the same lenght of time. If the speed of the wind is 24 mph, what is the speed of the plane in still air?
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Let the speed in still air be "x"
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With the wind DATA:
distance = 400 miles; rate = x+24 mph ; time = d/r = 400/(x+24) hrs.
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Against the wind DATA:
distance = 320 miles ; rate = x-24 mph ; time = d/r = 320/(x-24)
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EQUATION:
time with = time against
400/(x+24) = 320/(x-24)
5/(x+24) = 4/(x-24)
5(x-24) = 4(x+24)
5x-120 = 4x+96
x = 216 mph (rate of the plane in still air)
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Cheers,
Stan H.
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