New take. The problem can be described as a branching tree, where each copy-branch is cut off, leaving only 1 copy.
So, at step 2, we would’ve had 4 possibilities, 1 original and three copies, but branches of the copy were cut away, so we are left with three Joes, 1 original, 1 equally likely copy, and… 1 copy that’s twice as likely?
New take. The problem can be described as a branching tree, where each copy-branch is cut off, leaving only 1 copy.
So, at step 2, we would’ve had 4 possibilities, 1 original and three copies, but branches of the copy were cut away, so we are left with three Joes, 1 original, 1 equally likely copy, and… 1 copy that’s twice as likely?