Answer:
20 miles
Explanation:
If Maria has been riding for 2 1/2 hours and Aiden only for 2. That means that the first 4 miles she rode alone was for 1/2 hour. So that is the rate.
1/2 hour for every 4 miles
Maria rode for 2 1/2 hours divided by 1/2 hours is 5. So 5 x 4mi = 20 miles