Answer:
To solve this problem, we can use the formula:
Speed = Distance / Time
The total distance traveled by the plane is 3,000 + 600 = 3,600 miles. The total time taken is 2 hours 30 minutes, or 2.5 hours.
So, the speed of the plane is:
Speed = 3,600 miles / 2.5 hours = 1,440 miles per hour
Therefore, the answer is 1440 mph