Question 924155: A train travels 110 km in the same time that a plane covers 385 km. If the speed of the plane is 30 km per hr less than 4 times the speed of the train, find both speeds.
Found 2 solutions by TimothyLamb, MathTherapy:
Answer by TimothyLamb(4379)   (Show Source):
You can put this solution on YOUR website! x = speed of airplane
y = speed of train
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s = d/t
t = d/s
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airplane time:
t = 385/x
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train time:
t = 110/y
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t = 385/x = t = 110/y
385/x = 110/y
385y = 110x
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x = 4y - 30
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385y = 110x
x = 4y - 30
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put the system of linear equations into standard form
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110x - 385y = 0
x - 4y = -30
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copy and paste the above standard form linear equations in to this solver:
https://sooeet.com/math/system-of-linear-equations-solver.php
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solution:
x = speed of airplane = 210 kph
y = speed of train = 60 kph
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Answer by MathTherapy(10552)  (Show Source):
You can put this solution on YOUR website!
A train travels 110 km in the same time that a plane covers 385 km. If the speed of the plane is 30 km per hr less than 4 times the speed of the train, find both speeds.
Let speed of train be S
Then speed of plane is: 4S 30
Time it takes train to travel 110 km: 
Time it takes plane to travel 385 km: 
Since they cover their respective distances in the same amount of time, we then get:
110(4S 30) = 385(S) ------- Cross-multiplying
440S 3,300 = 385S
440S 385S = 3,300
55S = 3,300
S, or speed of train =  , or  km/h
Speed of plane = 4(60) 30, or 240 30, or  km/h
You can do the check!!
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