Question 1170057
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(1) Find the speed A with the jet stream by dividing distance by time; find the speed B against the jet stream the same way.<br>
(2) The speed A is the speed of the plane plus the speed of the jet stream; the speed B is the speed of the plane minus the speed of the jet stream.  That means the speed of the plane is the average of A and B (i.e., halfway between A and B); and then the speed of the jet stream is the difference between the speed of the plane and either A or B.<br>
An example, in case the words are hard to follow:<br>
speed with the jet stream: A = 400
speed against the jet stream: B = 320
speed of plane: halfway between A and B: 360
speed of jet stream: difference between 360 and either A or B: 400-360 = 40, or 360-320 = 40<br>