I am trying to calculate win chance for the following game.
We have 9 indexed cells. One cell is green. User can select N cells (1-8) and reveal them.
If the green cell was within revealed cells, then user won. What is the win probability for the given N number selected number, 1 green cell and 9 total cells?
You have $\frac N9$ chance of finding the green cell if you pick $N$ cells. Each pick has a disjoint $\frac 19$ chance of winning.