A jet plane traveling at 500 mph overtakes a propeller plane

A jet plane traveling at 500 mph overtakes a propeller plane traveling at 200 mph that had a 2-hour head start. How far from the starting point are the planes?

Solution

d=st Where d=distance, t=time, s=speed
d is the same for both planes.
500t=200(t+2) head start of 2 hr=t+2
500t=200t+400
300t=400
t=4/3 hr
500 * 4/3 = 2000/3 =666.67 mi