The 10% stacks additively, each time you do the deal, this status is applied to a different 10%. If you sacrifice 10 fingers, the entire world is guaranteed basic human needs (food, water, shelter, clothing, healthcate, etc…)
Nobody knows you saved them. Would you do it?
If everyone knows about the fact that you can do this deal, would that change your mind?
Wait wait, by saying 10% stacks each time, do you mean 10% of the original number, or 10% of the remaining number of people?
Like, for the sake of simplicity, 10 billion to start with, 10%, so 1 billion for the first finger. Then does it become 10% of the remaining 9 billion, so around 900 million, or another 10% of 10 billion?
I would likely still do it, even if all 10 fingers wouldn’t save humanity together, but if I could also pass this deal, it would be interesting to get 10 random people off the street and present the choice to them. If the collective has the solidarity necessary to want to save others, it shows just how justified it is for them to be saved.