Answer: each plane travelled for 40 hours.
Explanation:
Let x represent the speed of plane A. Plane B is flying 60mph faster than Plane A. It means that the speed at which plane B is flying is
(x + 60) mph
Plane B can fly 3040 miles in the same amount of time it takes Plane A to fly 2800 miles.
Time = distance/speed
Time taken by plane B to fly 3040 miles is
3040/(x + 60)
Time taken by plane A to fly 2800 miles is
2800/x
Since the time is the same, it means that
3040/(x + 60) = 2800/x
Cross multiplying, it becomes
2800(x + 6) = 3040x
2800x + 16800 = 3040x
3040x - 2800x = 16800
240x = 16800
x = 16800/240
x = 70 mph
The amount of time it takes for each plane to travel their respective distances is
2800/x = 2800/70 = 40 hours