A plane left at 3pm flying west at 450 miles per hour. At 3:30 pm another plane left the same airport flying west at 500 miles per hour. At what time did the second plane overtake the first plane? Solution first plane speed 450 mph second plane speed 500 mph rt=d RT=D 30 minutes head start=1/2 hour 450*(t+1/2)=500(t)divide by 50 9*(t+1/2)=10t 9t+4.5=10t simplify 4.5 hours =t They pass at 7:30 pm.