SOLUTION: When a train left Podunck and traveled West 70 KM/H, 2 hours later, another train left Podunck and traveled East at 90KM/H, how many hours had the first train traveled when they we

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Question 62030: When a train left Podunck and traveled West 70 KM/H, 2 hours later, another train left Podunck and traveled East at 90KM/H, how many hours had the first train traveled when they were 1420 KM apart?
Found 2 solutions by ankor@dixie-net.com, Nate:
Answer by ankor@dixie-net.com(22740) About Me  (Show Source):
You can put this solution on YOUR website!
When a train left Podunck and traveled West 70 KM/H, 2 hours later, another train left Podunck and traveled East at 90KM/H, how many hours had the first train traveled when they were 1420 KM apart?
:
Let t = westbound train time:
Let (t-2) = eastbound train time:
:
Dist = speed * time
:
70t + 90(t-2) = 1420
70t + 90t - 180 = 1420
160t = 1420 + 180
160t = 1600
t = 1600/160
t = 10 hrs the westbound train:
:
Check: 70(10) + 90(8) = 1420
:

Answer by Nate(3500) About Me  (Show Source):
You can put this solution on YOUR website!
First Train:
Rate: 70km/h
Time: t + 2
Second Train:
Rate: 90km/h
Time: t
The sum of the two train's distances is equal to the total distance between the two.
Distance = Rate * Time
First Train:
70(t + 2)
70t + 140
Second Train:
90(t)
90t
70t + 140 + 90t = 1420
160t = 1280
t = 8
First Train:
Rate: 70km/h
Time: t + 2 = 8 + 2 = 10
Second Train:
Rate: 90km/h
Time: t = 8