Question 1120831
In a large marathon, runners start the race in stages.
 Jorge started in group E and ran at a rate of 4.5 miles per hour.
 During the race he was passed by Luis who ran at a rate of 5 miles per hour and started in group H, 15 minutes after Jorge started.
 How far did Jorge run before he was passed by Luis?
;
let t = running time of J
Change 15 min to {{{1/4}}} hr, then
(t - {{{1/4}}}) = running of L
when L catches up with J, they will have traveled the same distance
:
A distance equation; dist = speed * time
5(t-{{{1/4}}}) = 4.5t
5t - {{{5/4}}} = 4.5t
5t - 4.5t = {{{5/4}}}
or 
.5t = 1.25
t = {{{1.25/.5}}}
t = 2.5 hrs
:
Find the distance J traveled 
2.5(4.5) = 11.25 mi
:
Check this, find the distance L traveled, his time was 2.25 hrs
2.25(5) =  11.25 mi