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A plane has a cruising speed of 200 miles per hour when there is no wind.
At this speed, the plane flew 500 miles with the wind in the same amount of time
as it flew 300 miles against the wind. Find the speed of the wind.
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Let x be the speed of the wind, in miles per hour.
Then the plane's effective speed flying with the wind is (200+x) mph;
effective speed flying against the wind is (200-x) mph.
Now we write the "time" equation
=
To solve it, first cross-multiply; then simplify and find x
500*(200-x) = 300*(200+x)
5*(200-x) = 3*(200+x)
1000 - 5x = 600 + 3x
1000 - 600 = 3x + 5x
400 = 8x
x = 400/8 = 50.
ANSWER. The speed of the wind is 50 miles per hour (rounded).
CHECK. = 2 hours with the windth.
= 2 hours against the windth. ! The flying time is the same: CORRECT !
Solved.