.
u - v = = 670 mi/h is the effective speed of the plane against the wind.
u + v = = 990 mi/h is the effective speed of the plane with the wind.
v = = 160 miles per hour is the speed of the wind.
For your info: the speed of the wind of 160 mi/h is more than the air speed in the eye of a hurricane.
The input data in the problem is NOT realistic.
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In this spot, a real problem from a real student could be placed, who really needs help - instead of these fantasies.
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Hello,
after posting my solution to you, I got your comment regarding my words "The input data in the problem is NOT realistic."
My solution is correct, and these my words are correct, too - there is no doubt.
It happens often that textbooks have errors/(mistakes).
In this case, as in other similar cases, you must say "Thanks" to me first for I solved the problem for you,
and then say "Thanks" to me again for pointing your attention that the input data is unrealistic.
And I really expect that you will do it.
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Regarding my words ". . . In this spot . . . " - it was a joke, obviously.
Excuse me, please, if you find it rude.