Question 902022
One car and the second car, and then bob.  Who is bob?


The rule for uniform rates of travel is RT=D for rate time distance.


The most needed unknown is time, call it t, for how long before the two cars "meet".  Both cars are working for the distance of 300 miles BUT NOT BOTH AT ALL the same time.  Fifteen minutes means one quarter of an hour.


____________________speed__________time__________distance
FIRST CAR___________80_____________t+1/4_________(_____)
SECOND CAR__________90______________t____________(_____)
Total______________________________________________300



Can you decide what to do with that tabulated data?