SOLUTION: carlos takes 15 minutes longer than janet does to make the 144 mile drive between two cities. janet drives 8 miles an hour faster. how fast do carlos and janet drive?

Algebra ->  Customizable Word Problem Solvers  -> Travel -> SOLUTION: carlos takes 15 minutes longer than janet does to make the 144 mile drive between two cities. janet drives 8 miles an hour faster. how fast do carlos and janet drive?      Log On

Ad: Over 600 Algebra Word Problems at edhelper.com


    

Question 820965: carlos takes 15 minutes longer than janet does to make the 144 mile drive between two cities. janet drives 8 miles an hour faster. how fast do carlos and janet drive?
Answer by josgarithmetic(39630) About Me  (Show Source):
You can put this solution on YOUR website!
Janet drives 8 mph FASTER than Carlos, so what speed does Carlos drive? This is a variable.

Let x = time for Janet to do the travel distance;
Let r = speed of Carlos;
time is in hours.

_______________speed________time_________distance
Janet___________8+r__________x___________144
Carlos__________(r)__________x+(1/4)_____144

Using R*T=D idea obtain the system of equations, highlight_green%28%28r%2B8%29x=144%29 and highlight_green%28r%28x%2B1%2F4%29=144%29
Two equations in two unknown variables.