SOLUTION: after robbing a bank in brigton the dalton brothers galloped away at 24 km/h. 15 minutes later the posse left at 28 km/h. how long did it take the posse to overtake the dalton brot

Algebra ->  Coordinate Systems and Linear Equations  -> Linear Equations and Systems Word Problems -> SOLUTION: after robbing a bank in brigton the dalton brothers galloped away at 24 km/h. 15 minutes later the posse left at 28 km/h. how long did it take the posse to overtake the dalton brot      Log On


   

Question 230064: after robbing a bank in brigton the dalton brothers galloped away at 24 km/h. 15 minutes later the posse left at 28 km/h. how long did it take the posse to overtake the dalton brothers?
Answer by josmiceli(19441) About Me  (Show Source):
You can put this solution on YOUR website!
How far did the D Bros get in 1/4 hr?
d+=+r%2At
d+=+24%2A%281%2F4%29 km
d+=+6 km
So, they had a 6 km headstart. Now I start my
stopwatch. I'll stop it when posse catches them
For posse:
(1) d%5Bp%5D+=+28t
For D Bros:
(2) d%5Bp%5D+-+6+=+24t
Substitute (1) in (2)
28t+-+6+=+24t
4t+-+6+=+0
4t+=+6
t+=+1.5 hrs
The posse overtakes them in 1.5 hrs
check answer:
(1) d%5Bp%5D+=+28t
d%5Bp%5D+=+28%2A1.5
d%5Bp%5D+=+42 km
and
(2) d%5Bp%5D+-+6+=+24t
d%5Bp%5D+-+6+=+24%2A1.5
d%5Bp%5D+=+36+%2B+6
d%5Bp%5D+=+42 km
OK