Question 834327
Tom and Liz used to live 23.5 miles apart.
 They would meet by Liz riding her bicycle 10 mph towards Tom while he rides his moped towards Liz at 18 mph.
 If Liz leaves 15 minutes before Tom, how long is she on her bicycle before she meets him?
:
Change 15 min to .25 hrs (we are dealing mph)
:
Let t = Liz's traveling time
then
(t-.25) = Tom's traveling time (left 15 min later than Liz)
:
Write a Distance equation: Dist = speed * time
:
Liz's dist + Tom's dist = 23.5 mi
10t + 18(t-.25) =  23.5
10t + 18t - 4.5 = 23.5
28t = 23.5 + 4.5
28t = 28
t = 28/28
t = 1 hr is Liz's traveling time
:
:
Check this by finding the dist each traveled
10*1 = 10 mi
18(.75) = 13.5 mi
----------------
Total dist 23.5