Answer:
91.7 mph west
Step-by-step explanation:
The average velocity is the ratio between the displacement and the time taken:

where d is the displacement and t the time taken.
First of all, we need to find the net displacement. We know that the car moves
200.0 miles west + 75.0 miles west = 275.0 miles west
While the total time taken is

So now substituting into the equation above, we find the average velocity:

And the direction is the same as the displacement, so west.