Answer: 1.25 miles per minute
Explanation:
Average speed is the rate of change of total distance covered per unit time.
i.e Average speed = (Total distance / Time taken)
Total distance covered = (25miles + 40 miles + 70 miles + 15 miles)
= 150 miles
Total time taken = ( 15 minutes + 30 minutes + 1 hour + 15 minutes) = 120 minutes
Since 60 minutes = 1 hour, the total time taken is 120 minutes
Now, apply Average speed = (Total distance / Time taken)
= (150 miles / 120 minutes)
= 1.25 miles per minutes
Thus, Joseph drove with an average speed of 1.25 miles per minute.
