Twice last month, Judy rented a car from a car rental company and traveled around the southwest on business. The company rents its car for a daily fee plus an additional charge per mile driven. Judy recalls that her first trip lasted 4 days, she drove 450 miles and the rental car costed her $222. On her second business trip she drove 200 miles in 3 days and paid $139 for the rental. Find the daily fee and find the mileage charge.

Question

anonymous · Answer

We can set up a system of equations. let d=daily fee and let m=cost per mile

use the elimination method.
4d+450m=222 <------*-3
3d+200m=139  <---------*4
----------------
-12d-1350m=-666
12d+800m=556

add them together, d cancels out.

-550m=-110
m=.2

Substitute m into original equation and solve for d.

4d+450(.2)=222
4d+90=222
4d=132
d=33


So daily charge is $33 and cost per mile is $.20