Answer:
Plane 1 was in the air for 6 hours, Plane 2 took 4.5 hours.
Step-by-step explanation:
subtract Plane 2's miles by Plane 1's: 675. Thus, it took Plane 1 1.5 hours to travel 675 miles. Divide the miles by hours and you get 450 MPH. Then, divide each mile figure by the MPH figure to get the time that each plane was in the air: Plane 1 was in the air for 6 hours, Plane 2 took 4.5 hours.
I hope that I was fast enough, and that this is correct.