Answer: 3 miles per hour.
Explanation:
Given : Aubrey can walk
miles in
hours.
We can first convert the mixed fraction into improper fraction.
i.e. Distance =
Time =
Now, the average speed in miles per hour =

i.e. the average speed in miles per hour =

i.e. the average speed in miles per hour =

i.e. the average speed in miles per hour =

Hence, her average speed is 3 miles per hour.