Find the average speed of a plane that leaves bristol at 14.00 and lands in rome at 17.15.the distance is 1200 miles

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Distance between Bristol and Rome that the plane covers = 1200 miles
Starting time of the plane from Bristol = 14:00 hrs
Landing time of the plane in Rome = 17:15 hrs
Then
Total time taken by the plane to travel from Bristol to Rome = 17:15 - 14:00 hours
                                                                                               = 3 .15 hours
So
The average speed of the plane = 1200/3.15 miles per hour
                                                    = 380.95 miles per hour
From the above deduction we can conclude that the average speed of the plane traveling from Bristol to Rome is 380.95 miles per hour.