You can infer from this problem that for every 100 m that John was able to run, it takes him 9.93 seconds. To get how much time is needed for 26 – mile marathon, you need to divide 26 miles by 100 meters. But first, you need to convert 26 miles to meters first.
1 mile = 1,609.34 meters
26 miles = 41,842.84 meters
41,824.84 meters / 100 meters = 418.43 x 9.93 seconds = 4,155 seconds or 69.25 minutes