SOLUTION: A plane flies 470 miles with the wind and 310 against the wind in the same length of time. If the speed of the wind is 40 mph find the speed of the plane in still air.
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Question 764208: A plane flies 470 miles with the wind and 310 against the wind in the same length of time. If the speed of the wind is 40 mph find the speed of the plane in still air. Answer by Cromlix(4381) (Show Source):
You can put this solution on YOUR website! Speed with wind = x + 40
Speed against wind = x - 40
470/x + 40 = 310/x - 40
Cross multiply
470(x - 40) = 310(x + 40)
470x - 18800 = 310x + 12400
470x - 310x = 12400 + 18800
160x = 31200
x = 195mph in still air.
Hope this helps.
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