SOLUTION: The speed of a passenger train is 20 mph faster than the speed of a freight train the passenger train travels 280 miles in the same time as the freight train to travel 180 miles. f

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Question 1008940: The speed of a passenger train is 20 mph faster than the speed of a freight train the passenger train travels 280 miles in the same time as the freight train to travel 180 miles. find the speed of each train.
what is the speed of the passenger train
what is the speed of the freight train
Answer by josmiceli(19441) About Me  (Show Source):
You can put this solution on YOUR website!
Let +s+ = the speed of the passenger train
+s+-+20%5D+ = the speed of the freight train
Let +t+ = time in hours for both trains
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Equation forpassenger train:
(1) +280+=+s%2At+
Equation for freight train:
(2) +180+=+%28+s-20+%29%2At+
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(1) +t+=+280%2Fs+
Substitute (1) into (2)
(2) +180+=+%28+s-20+%29%2A%28+280%2Fs+%29+
(2) +180s+=+280s+-+5600+
(2) +100s+=+5600+
(2) +s+=+56+
and
+s+-+20+=+36+
The speed of the passenger train is 56 mi/hr
The speed of the freight train is 36 mi/hr
-------------------------------------
check:
(1) +280+=+56%2At+
(1) +t+=+5+
and
(2) +180+=+%28+56-20+%29%2At+
(2) +180+=+36t+
(2) +t+=+5+
OK