Question 1142254
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Time is distance divided by rate.<br>
Since the times with and against the wind are the same, time is also the DIFFERENCE in distances divided by the DIFFERENCE in rates.<br>
The difference in the two rates is twice the wind speed (because the wind speed adds to the speed in one direction and subtracts from it in the other direction).<br>
So the difference in rates is 40mph; the difference in distances is 200 miles.  So the time for each flight is 200/40 = 5 hours.<br>
So the speed of the plane with the wind is 1050/5 = 210mph; that makes the speed of the plane in still air 210-20 = 190mph.