Question 1049707
The example is a typical one-of-these exercises:


r, 40 miles per hour, slow car
R, 55 miles per hour, fast car
h,  0.5 hour
-
Time quantities come from time points in the description and would need to be readjusted to finish the solution.
-
d, unknown distance upon catchup
t, time for fast car to catchup to slow car



<pre>
               SPEEDS      TIME      DISTANCE

EARLY SLOW       r          t+h        d

LATE FAST        R           t         d
</pre>


Constant Travel Rates Rule, if travel rate is K, time is T, distance is D, {{{D/T=K}}}.


{{{system(r(t+h)=d,Rt=d)}}}
Solve the system for t, and if desired, for d.