<PRE><B>Question 463262</B>
A runner started a course at an average speed of 6mph. Two hours later, a cyclist traveled the same course at an average speed of 12mph. How long after the runner started did the cyclist overtake the runner?
...
let x=hrs cyclist takes to overtake runner
travel time of runner=x 
travel time of cyclist=x-2
both runner and cyclist traveled the same distance
distance=travel time*speed
6x/60=12(x-2)/60
6x=12x-24
6x=24
6=4 hrs
ans:
cyclist overtook the runner in 4 hrs</PRE>