Question 548161: With a tail wind, a jet flew 2000 miles in 4 hours. The jet's return trip against the same wind required 5 hours. Find the jet's speed and the wind speed. I got 500,0. I know that's wrong.
Answer by mananth(16946)   (Show Source):
You can put this solution on YOUR website! plane speed speed =x mph
wind speed =y mph
against wind , x-y 5 hours
with wind , x+y 4 hours
Distance = same= 2000 miles
t=d/r against wind
2000/(x-y)=5.00
5(x-y)=2,000.00
With wind
5x-5y=2000 ....................1
2000/(x+y)=4.00
4.00(x+y)=2000
4.00x+4y=2000 ...............2
Multiply (1) by 4.00
Multiply (2) by 5.00
we get
20 x + -20 y = 8000
20 x + 20 y = 10000
40 x = 18000
/ 40
x = 450 mph
plug value of x in (1)
5 x -5 y = 2000
2250 -5 y = 2000
-5 y = 2000 -2250
-5 y = -250
y = 50 mph
plane speed 450 mph
wind 50 mph
m.ananth@hotmail.ca
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