math
posted by Kate .
A train left Podunk and traveled west at 70 km/h. Two hours later, another train left Podunk and traveled east at 90 km/h. How many hours had the first train traveled when they were 1420 km apart?
How do you solved this?

I translated your English into Math and got
70t+140 + 90t = 1420
Take it from there. 
where did you get 140 from?

didn't the first train go for 2 hrs at 70 km/h ? How far did it go in that time ?

Got it. Thank you very much

Welcome!

a train left podunk and traveled north at 75 km/h. two hours later, another train left podunk and travled in the same direction at 100 km/h. how many hours had the first train traveled when the second train overtook it?
can someone help set this up? 
8 hrs.....

aly, its not 8 hrs......

You would set them up equal to each other.
Looks like.
75T + 150 = 100T
T= 6