Divide 5 by 89 and you get a=17.8
The billiard balls without replacement.
Let's say there are 10 billiard balls 5 red and 5 blue.
If you pick a blue ball on the first pick you had a 5/10 chance
Now your chances of getting a red are only 5/9.
What happened on the first pick affects what happens on the second (making it dependent)
Is it 25 or no I guess it’s not