SOLUTION: A freight train and an express train leave towns 390 km apart, traveling toward one another. The freight train travels 30 km per hr slower than the express train. They pass one an

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Question 214694This question is from textbook
: A freight train and an express train leave towns 390 km apart, traveling toward one another. The freight train travels 30 km per hr slower than the express train. They pass one another 3 hr later. What are their speeds? This question is from textbook

Answer by stanbon(75887) About Me  (Show Source):
You can put this solution on YOUR website!
A freight train and an express train leave towns 390 km apart, traveling toward one another. The freight train travels 30 km per hr slower than the express train. They pass one another 3 hr later. What are their speeds?
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Problems of this type are all based on the equation distance = rate*time
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Freight DATA:
distance = x miles ; time = 3 hrs ; rate = d/t = x/3 mph
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Express DATA:
distance = (390-x) miles ; time = 3 hrs ; rate = (390-x)/3
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Equation:
rate - rate = 30
(390-x)/3 - x/3 = 30 mph
390-x - x = 90
-2x = -300
x = 150 (distance for the freight train(
x/3 = 50 mph (rate for the freight train)
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390-150 = 240 (distance for the express)
240/3 = 80 mph (rate for the express train)
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Cheers,
Stan H.