SOLUTION: A plane flies 450 miles with the wind and 350 miles against the wind in the same length of time. If the speed of the wind is 28 mph, what is the speed of the plane in still air?

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Question 370080: A plane flies 450 miles with the wind and 350 miles against the wind in the same length of time. If the speed of the wind is 28 mph, what is the speed of the plane in still air?
Answer by ewatrrr(24785) About Me  (Show Source):
You can put this solution on YOUR website!


Hi,

d = rt   t =d/r  

Times are the same.

Let r represent the speed in still air

450%2F%28r+%2B+28%29+=+350%2F%28+r+-28%29

cross multiply to solve

450(r-28) = 350(r+28)

450r - 450*28 = 350r + 350*28

100r = 800*28

r = 8*28 = 224mph is the speed of the plane in still air

checking our answer

450/252 = 350/196 = 1.79 hr