<PRE><B>Question 221967</B>
two trains depart from a station, traveling in opposite directions. 
the train that departs at 6:30 AM travels 15 km/h faster than the train that
 departs at 6 AM. At 7 AM they are 135 km apart.
 Determine the rate of each train.
:
Let s = speed of the train that departs at 6 AM
then
(s+15) = speed of the train that departs at 6:30
:
At 7 AM:
the 1st train travel time is 1 hr
the 2nd train travel time is .5 hr
:
Write a distance equation: Dist = time * speed
:
1s + .5(s+15) = 135
1s + .5s + 7.5 = 135
1s + .5s  = 135 - 7.5
1.5s = 127.5
s = {{{127.5/1.5}}}
s = 85 mph is the speed of the 6 AM train
:
85 + 15 = 100 mph is the speed of the 6:30 train
;
;
Check solution in the distance equation
1*85 + .5*100 = 
85 + 50 = 135</PRE>