SOLUTION: a train travels 150 km in the same time that a plane covers 400 km. if the speed of the plane is 20 km per hr. less than 3 times the speed of the train, find both speeds.

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Question 403555: a train travels 150 km in the same time that a plane covers 400 km. if the speed of the plane is 20 km per hr. less than 3 times the speed of the train, find both speeds.
Answer by stanbon(75887) About Me  (Show Source):
You can put this solution on YOUR website!
a train travels 150 km in the same time that a plane covers 400 km.
if the speed of the plane is 20 km per hr. less than 3 times the speed of the train, find both speeds.
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Train DATA:
distance = 150 km ; rate = x km/h ; time = 150/x hrs
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Plane DATA:
distance = 400 km ; rate = 3x-20 km/h ; time = 400/(3x-20) hrs
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Equation:
time = time
150/x = 400/(3x-20)
---
3/x = 8/(3x-20)
---
3(3x-20) = 8x
9x-60 = 8x
x = 60 km/h (train rate)
---
3x-20 = 160 km/h (plane rate)
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Cheers,
Stan H.
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