"Assuming the group consists only of “the two fathers and the two sons” (i.e., every person in the group is counted as a father and/or a son), the total number of distinct people can only be 3 or 4.
Reason: you are taking the union of a set of 2 fathers and a set of 2 sons. The union size is 2+2−overlap, so it is 4 if there’s no overlap and 3 if exactly one person is both a father and a son. (It cannot be 2 in any ordinary family tree.)"
Here it clearly states its assumption (finite set of people that excludes non-mentioned people, etc.)
https://chatgpt.com/share/698b39c9-2ad0-8003-8023-4fd6b00966...
Great job, AI labs! It's almost TOO useful
Riddle me this, why didn’t you do a better riddle?
Person 2: 'Okay, I have no idea how many chairs to grab, not enough information' - nobody ever
(Person 2 has no ability to contribute to anything of economic value.)
Three people — a grandfather, his son, and his grandson. The grandfather and the son are the two fathers; the son and the grandson are the two sons.