Posted by angie on Tuesday, November 15, 2011 at 2:34am.
a train left podunk and traveled north at 75 km/h. two hours later, another train left podunk and traveled in the same direction at 100 km/h. how many hours had the first train traveled when they were 1420 km apart?

math  Reiny, Tuesday, November 15, 2011 at 8:10am
When they are 1420 km apart let the time taken by the first train be t hrs,
then the time taken by the second train be t2 hrs
distance traveled by 1st train = 75t
distance traveled by 2nd train = 100(t2)
what do you know about the two distances?