<PRE><B>Question 836146</B>
Opposite directions, tells you sum of their distances is 640 miles at the given time of 4 hours.


Eastbound train is the FASTER one.

r = rate of the slower train.



________________speed_____________time___________distance
EastFast________r+20______________4__________(____)
WestSlow_________r_______________4___________(____)
Total_____________________________________________640



Formula for uniform travel rate R*T=D gives expressions for the distances.


________________speed_____________time___________distance
EastFast________r+20______________4______________(r+20)*4
WestSlow_________r_______________4________________r*4
Total_____________________________________________640


Total of distances gives equation to solve for r:
{{{highlight((r+20)*4+4*r=640)}}}
Once finding r, you can compute r+20.</PRE>