SOLUTION: A passenger train leaves New York City traveling west at 130 km/hr. Three hours later, a freight train leaves the same station, traveling west at 160 km/hr. How many hours will e
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Question 122400: A passenger train leaves New York City traveling west at 130 km/hr. Three hours later, a freight train leaves the same station, traveling west at 160 km/hr. How many hours will each train travel before the second train catches up with the first? Answer by ankor@dixie-net.com(22740) (Show Source):
You can put this solution on YOUR website! A passenger train leaves New York City traveling west at 130 km/hr. Three hours later, a freight train leaves the same station, traveling west at 160 km/hr. How many hours will each train travel before the second train catches up with the first?
:
One important fact to remember in these kind of "catch-up" problems is:
When they catch up they will have traveled the same distance.
We can make a simple equation from this fact:
:
Let t = time required for the 2nd train to catch up
then
(t+3) = travel time of the 1st train when it is caught
:
Dist = speed * time
:
2nd train dist = 1st train dist
160t = 130(t+3)
160t = 130t + 390
160t - 130t = 390
30t = 390
t =
t = 13 hrs for the 2nd train to catch up
;
Check solution by finding the distance, they should be equal
1st train time 13 + 3 = 16 hr
160 * 13 = 2080 km
130 * 16 = 2080 km; confirms our solution
:
This wasn't that hard, was it?