Final answer:
The plane flew for 12 hours.
Step-by-step explanation:
To find the number of hours the plane flew, we can use the formula:
Time = Distance / Speed
Given that the total distance flown by the plane is 6,240 miles and its speed is 520 miles per hour:
Time = 6,240 / 520 = 12 hours
Therefore, the plane flew for a total of 12 hours.