SOLUTION: Two trains leave a station at the same time but travel in opposite directions. One moves at a constant speed of 140 km/h while the other rolls along at a speed of 120 km/h. How lon

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Question 1053702: Two trains leave a station at the same time but travel in opposite directions. One moves at a constant speed of 140 km/h while the other rolls along at a speed of 120 km/h. How long does it take for the distance between the trains to reach 390 km?
Answer by ikleyn(52771) About Me  (Show Source):
You can put this solution on YOUR website!
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390%2F%28140%2B120%29 = 390%2F260 = 3%2F2 hour = 1 hour and 30 minutes.

The sum (140+120) in the denominator is the rate of increasing the distance between the trains (in km/h).