To determine the average speed Mary would need to make the trip in 5 hours, we first need to recall the formula for speed, which is:

$\text{Speed} = \frac{\text{Distance}}{\text{Time}}$

Mary drove 455 miles, so if she wants to complete this distance in 5 hours, we can calculate the necessary speed using the formula:

$\text{Speed} = \frac{455 \text{ miles}}{5 \text{ hours}}$

Now, we compute the division:

$\text{Speed} = 91 \text{ miles per hour}$

So, Mary would need to drive at an average speed of 91 miles per hour to complete the 455-mile trip in 5 hours.

Would you like any further details or have any questions?

Here are 8 related questions that expand on this information:

1. How do you calculate average speed when given distance and time?
2. What is the formula for distance if you know speed and time?
3. How do changes in speed affect travel time for a fixed distance?
4. If Mary took 8 hours for the trip, what would her average speed be?
5. How can you convert miles per hour to kilometers per hour?
6. What factors can affect a driver's average speed on a long trip?
7. If the distance was increased to 600 miles, what would be the required speed to complete it in 7 hours?
8. How does knowing average speed help in planning travel schedules?

Tip: When planning long trips, always account for potential delays such as traffic, rest stops, and weather conditions, as they can significantly affect your travel time.