SOLUTION: a plane travels 390 miles in 2 hours traveling with the wind, going against the wind, the plane travels 330 mile in the same time. find the speed of the plane in still air and the

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Question 1123584: a plane travels 390 miles in 2 hours traveling with the wind, going against the wind, the plane travels 330 mile in the same time. find the speed of the plane in still air and the speed of the wind.
Answer by josmiceli(19441) About Me  (Show Source):
You can put this solution on YOUR website!
Let w = the speed of the wind
Let s = the speed of the plane in still air
——————-
Flying with the wind
(1) +390+=+%28+s%2Bw+%29%2A2+
Flying against the wind:
(2) +330+=+%28s-+w+%29%2A2+
—————————————
(1) +195+=+s+%2B+w+
(2) +165+=+s+-+w+
Add the equations
+2s+=+360+
+s+=+180+
And
(1) +195+=+180+%2B+w+
(1) +w+=+15+
————————————-
Check:
(2) +330+=+%28+s-w+%29%2A2+
(2) +330+=+165%2A2+
(2) +330+=+330+
OK