SOLUTION: A plane can fly 312 miles with the wind in 3 hours, while it takes the same plane 4 hours to fly the same distance against the wind. Find the speed of the plane in still air, and t

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Question 1037342: A plane can fly 312 miles with the wind in 3 hours, while it takes the same plane 4 hours to fly the same distance against the wind. Find the speed of the plane in still air, and the speed of the wind.
Found 2 solutions by josgarithmetic, Alan3354:
Answer by josgarithmetic(39617) About Me  (Show Source):
You can put this solution on YOUR website!
                RATE           TIME         DISTANCE
WITH            r+w             3            312               
AGAINST         r-w             4            312

system%28%28r%2Bw%293=312%2C%28r-w%294=312%29
Solve the LINEAR system for r and w.

Algebra steps:
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system%28r%2Bw=312%2F3%2Cr-w=312%2F4%29
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system%28r%2Bw=104%2Cr-w=78%29
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r%2Bw%2Br-w=104%2B78
2r=182
highlight%28r=91%29
.
.
.

Answer by Alan3354(69443) About Me  (Show Source):
You can put this solution on YOUR website!
A plane can fly 312 miles with the wind in 3 hours, while it takes the same plane 4 hours to fly the same distance against the wind. Find the speed of the plane in still air, and the speed of the wind.
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Find the 2 groundspeeds, downwind and upwind.
The plane's airspeed is the average of the 2.
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Windspeed is the difference between groundspeed and airspeed.