Question 851510
RT=D for rate time distance.


These runners are on the same trail, going the same length, and we are assuming starting at the same point in time.


_________________speed__________time___________distance
one runner________5_____________t______________5t
other runner______4____________t+1/2_________4(t+1/2)


The distances of each runner are equal.  Solve that equality for time t, and then you can find the distance.