Question 314574: If a plane travels 500miles per hour with wind and 400mile per hour against the wind, find the speed of the plane is stil air? Answer by solver91311(24713) (Show Source):
Let represent the speed of the plane in still air. Let represent the speed of the wind.
The overall speed when the wind and the airplane are going in the same direction is the speed in still air PLUS the speed of the wind, which is to say:
By similar logic, when the airplane is flying into the wind, the overall speed is the speed in still air MINUS the speed of the wind, which is to say:
Add the two equations:
Which is then the speed in still air. I still don't know what the speed in stil [sic] air is. No, there is no Santa Claus and spelling DOES count, even when doing mathematics.
