SOLUTION: A train leaves the station at 6:00 PM traveling west at 80 mi/h. On a parallel track, a second train leaves the station 3 hours later traveling west at 100 mi/h. At what time will

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Question 549899: A train leaves the station at 6:00 PM traveling west at 80 mi/h. On a parallel track, a second train leaves the station 3 hours later traveling west at 100 mi/h. At what time will the second train catch up with the first?
Answer by josmiceli(19441) About Me  (Show Source):
You can put this solution on YOUR website!
The 1st train has a head start of
+80%2A3+=+240+ mi
Start a stopwatch when the 2nd train leaves
Let d = distance 2nd train goes until they meet
Let t = time on stopwatch when they meet
---------------
2nd train:
+d+=+100t+
1st train:
+d+-+240+=+80t+
-----------------
By substitution,
+100t+-+240+=+80t+
+20t+=+240+
+t+=+12+
This is 12 hrs after the 2nd train leaves at 6 PM + 3 = 9 PM
The 2nd train catches up with the 1st train at 9 AM the next day
-----------------
check answer:
+d+=+100%2A12+
+d+=+1200+
and
+d+-+240+=+80%2A12+
+d+=+240+%2B+960+
+d+=+1200+
OK