Answer:
50 miles / hours.
Explanation:
Speed may be defined as the distance covered by the object per unit time.
Speed =

the distance of the business trip = 375 miles.
the time taken by the business trip = 7 hours 30 minutes = 7.5 hrs.
Speed =

Speed = 50 miles / hours.
Here, the average of miler per hour is 50 miles / hours.