Answer:
Elena's speed is 5 miles/hour
Step-by-step explanation:
The speed is defined as the covered distance per unit time. The distance covered is the length of the circular track which is given as of a mile. We also know that she completes each lap in of an hour. To get her speed, we have divide the distance covered by the time taken to cover this distance and you come out with 5. She can run 5 miles each hour. Or in other words you take 20 divided by 4 you get 5
