In the discrete math quiz level 2, I calculated the answer to be 386, or half of the given answer. It seems that the given solutions double-count by including a partition of the original set of 12 members into a subset of n members and its complement as a distinct partition from a subset of 12 - n members and its complement. You only need to count the different subsets with 1 to 5 members who have the property that the set and its subset are both selfish.
If I am wrong please explain my mistake.
Thanks, Fredric Kardon