It is impossible to run that fast, but if it were, it would take 2 hours.
100 miles at 100 mph would take 1 hour
It would take 12 minutes to drive 20 miles at 100 mph.
It would take: 1 hour at 100 mph or 2 hours at 50 mph
3 minutes
48 minutes.
It would take 15 minutes to drive 25 miles at 100 mph.
(100 miles)/[(40 miles)/hour] = 2.5 hours
100 hours.
42 minutes
6 minutes
2 hours
At an average 75 mph: 100 hours