I would say 9 hours because if he is going a speed of 8 mph and he needs to go 72 miles, it would only take him 9 hours to get there since it’s Miles Per Hour.
Explanation:
72 divided by 8 is 9. So if Pablo is going 8 miles per hour and has 72 miles to bike, then it would take him 9 hours to do so. Hope this helped!