<PRE><B>Question 783285</B>
A passenger train leaves a depot 1.5 h after a freight train leaves the same depot.
 The passenger train is traveling 15 mph faster than the freight train.
 Find the rate of each train if the passenger train overtakes the freight train in 3.5 h.
:
No reason to change it into a fraction. When the pass train overtakes the freight, they will have traveled the same dist. Dist = time * speed
:
let s = speed of the freight
then
(s+15) = speed of the pass train
:
Travel time of the pass train given as 3.5 hrs
Travel time of the freight: 3.5 + 1.5 = 5 hrs
:
 5s = 3.5(s+15)
 5s = 3.5s + 52.5
 5s - 3.5s = 52.5
 1.5s = 52.5
  s = 52.5/1.5
  s = 35 mph is the speed of the freight
then obviously, 
 50 mph is the speed of the pass train
:
:
We can confirm this by finding the actual dist each traveled
then should be the same
3.5 * 50 = 175 mi
5 * 35 = 175 mi
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