SOLUTION: Allison and Rachel are taking a trip together. They decide to share the driving responsibilities for the 480 mile drive. Allison drove at an average rate of 50 mph and Rachel drove

Algebra ->  Customizable Word Problem Solvers  -> Travel -> SOLUTION: Allison and Rachel are taking a trip together. They decide to share the driving responsibilities for the 480 mile drive. Allison drove at an average rate of 50 mph and Rachel drove      Log On

Ad: Over 600 Algebra Word Problems at edhelper.com


    

Question 349632: Allison and Rachel are taking a trip together. They decide to share the driving responsibilities for the 480 mile drive. Allison drove at an average rate of 50 mph and Rachel drove at an average rate of 40 mph. If Allison drover 45 minutes more than Rachel, then how far did Rachel drive?
Answer by josmiceli(19441) About Me  (Show Source):
You can put this solution on YOUR website!
For Allison:
d+=+r%2At
d+=+50t
For Rachel:
480+-+d+=+40%2A%28t+-+3%2F4%29
----------------------
By substitution:
480+-+50t+=+40t+-+30
90t+=+510
t+=+5.667
d+=+50t
d+=+283.333
Rachel drove:
480+-+283.333+=+196.667 mi
check answer:
480+-+d+=+40%2A%28t+-+3%2F4%29
480+-+283.333+=+40%2A%285.667+-+.75%29
196.667+=+40%2A4.9167
196.667+=+196.667