<PRE><B>Question 853229</B>
 An airplane made a trip of 200 miles against the wind in 1 hour. returning with the wind, the trip took only 50 minutes. Find the speed of the plane in calm air and the speed of the wind
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let x=speed of plane in calm air
let y=speed of wind
x+y=speed of plame with the wind
x-y=speed of plame against the wind
distance/speed=travel time
50 min=5/6 hr
..
2 equations:
200/(x-y)=1(against the wind)
200/(x+y)=5/6(with the wind)
..
x-y=200
5x+5y=1200
..
5x-5y=1000
5x+5y=1200
add
10x=2200
x=220
y=x-200=20
speed of plane in calm air=220 mph
speed of wind=20 mph


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