Anybody familiar with the hat riddle?
https://ed.ted.com/lessons/can-you-solve-the-prisoner-hat-riddle-alex-gendler
Watched the question and this is what I came up with, will watch the answer now-
Person in the back will never guess his own hat color so instead he sets everyone else up. He will say the color that has even amount of hats among the 9.
Since their are 9 people ahead of him, there can’t be an even distribution of black and white hats among those 9. For example if there are 6 black and 3 white, the person in the back can say Black to signal that black is even. Or there are 4 white and 5 black, he will say White. If he says Black, now the person in front of him can either see that a) there are in fact an even number of black hats, and therefore his hat must be white, or b) there are odd number of black hats, meaning his hat is black.
Now, if 2nd person says black, he is able to guess right while also signaling to the 3rd person that there are odd amount of black hats, and he can easily guess his color as well. And so on until they all get saved from these evil aliens.