SOLUTION: An airplane can fly 90 miles against the wind in the same time it takes to fly 110 miles with the wind. If the wind speed is 25 mph, what is the speed of the airplane in still air?
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Question 1010198: An airplane can fly 90 miles against the wind in the same time it takes to fly 110 miles with the wind. If the wind speed is 25 mph, what is the speed of the airplane in still air? Answer by fractalier(6550) (Show Source):
You can put this solution on YOUR website! Rate times time equals distance, or rt=d and t = d/r.
Call the rate of the plane in still air, r. Then we write
Now cross-multiply and solve giving us
90(r+25) = 110(r-25)
90r + 2250 = 110r - 2750
-20r = - 5000
r = 250 mph
