Final answer:
John's average speed for the whole journey is 52.5 km/h.
Step-by-step explanation:
To find John's average speed for the whole journey, we can use the formula:
Average Speed = Total Distance / Total Time
John drove for 6 hours at a rate of 50 km/h, so he covered a distance of 6 x 50 = 300 km. He also drove for 2 hours at a rate of 60 km/h, so he covered a distance of 2 x 60 = 120 km. The total distance for the whole journey is 300 + 120 = 420 km.
The total time for the whole journey is 6 + 2 = 8 hours.
Therefore, John's average speed for the whole journey is 420 km / 8 hours = 52.5 km/h.