Question 495922
A train leaves Miami at 1:00p.m. 
The second train leaves the same city in the same direction at 6:00p.m.
 The second train travels 105mph faster than the first. 
If the second overtakes the first at 9:00p.m. 
what is the speed of each of the two trains?
:
From the above information, we know:
The 2nd train overtakes the 1st train in 3 hrs
The travel time of the 1st train will be 8 hrs, when it's overtaken
:
Let s = speed of the 1st train
then
(s+105) = speed of the 2nd train
:
When 2nd train overtakes the 1st, they will have traveled the same distance
Write a distance equation; dist = speed * time
:
8s = 3(s+105)
8s = 3s + 315
8s - 3s = 315
5s = 315
s = {{{315/5}}}
s = 63 mph is the speed of the 1st train
and
63 + 105 = 168 mph is the speed of the 2nd train
:
:
Check this by finding the distance each travel; they should be equal
63*8 = 504 mi
168*3 = 504 mi