Suppose that when the rabbit wakes up, the tortoise still has x meters to reach the finish line.

5000+x=5x+ 100

x= 1225

So the rabbit ran away10000-5000-1225 = 3775 meters and fell asleep.

At this time, the tortoise ran 3775 \ 5 = 755 meters.

Subtract the distance that the tortoise ran when the rabbit slept, and then subtract the luck that the tortoise reached the finish line when the rabbit woke up.

10000- 1225-755=8020