<PRE><B>Question 152792</B>
What I needed to do to start this problem finally hit me.

1. You need to figure how far Train A travels in 15 minutes. We use this to determine the distance between the two trains when Train B leaves its station at 12:15.

2.  If 90/4=22.5 then 450-22.5=427.5 miles (This is the distance between Train A and Train B at 12:15

3.  Now you just plug your numbers into the d=rt formula

450 - 22.5 = 90t + 100t
427.5 = 190t
2.25 = t

So the time traveled after the 12:15 start time is 2h 15m
Therefore the time that the trains pass each other will be 2:30 PM


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