Question 37771
475(t+20)=500t or 475t+9500=500t or 9500=25t or t=380 so the second plane 

overtakes the first plane after 380 min or 6 1/3 hours.

thus the Cleveland plane was flying only 6 hours (20 minutes 1/3 hour - later 

than the Louisville plane thus 6*500 or 3,000 miles from Cleveland