SOLUTION: Jay flew an airplane 500km against the wind in the same time it took him to fly it 600km with the wind. The speed of the wind was 20km/h. What was the average speed of the airplane
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-> SOLUTION: Jay flew an airplane 500km against the wind in the same time it took him to fly it 600km with the wind. The speed of the wind was 20km/h. What was the average speed of the airplane
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Question 133700: Jay flew an airplane 500km against the wind in the same time it took him to fly it 600km with the wind. The speed of the wind was 20km/h. What was the average speed of the airplane? Answer by stanbon(75887) (Show Source):
You can put this solution on YOUR website! Jay flew an airplane 500km against the wind in the same time it took him to fly it 600km with the wind. The speed of the wind was 20km/h. What was the average speed of the airplane?
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Let speed of the plane be "p
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Against-the-wind data:
Distance= 500km ; Rate = p-20 kph ;Time = d/r = 500/(p-20).
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With-the-wind DATA:
Distance = 600 km ;Rate = p+20 kph ; Time = d/r = 600/(p+20) .
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EQUATION:
time with = time against
600/(p+20) = 500/(p-20)
6/(p+20) = 5/(p-20)
Cross-multiply to get:
6p-120 = 5p+100
p = 220 kph (average speed of the plane)
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Cheers,
Stan H.
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