We have been given that for a set amount of time, the distance Kirk can run is directly related to his average speed. Kirk can run 3 miles while running 6 miles per hour. We are asked to find the distance covered if his speed increases 10 miles per hour in same time.
Now, we need to find distance covered at a rate of 10 miles per hour in 0.5 hour.
Therefore, Kirk can run 5 miles in same amount of time at a rate of 10 miles per hour.