Too much pure decision theory gets boring. That is why I like to intermix it with puzzles and games which are related in some way to decision making and logic. But making up clever puzzles is difficult, and so I comb the Internet to find good examples. Today I am taking a slight variation of one of the fine puzzles that can be found here.

The puzzle is deceptively simple. And I like it because it is presented backward with answers first and question to follow.

The possible answers are:

A. Answer A

B. Answer A or B

C. Answer B or C

where the A, B, and C are self-referential. That is, If the Answer is A, then the answer is “Answer A.” Is that confusing?

The puzzle is that this puzzle has one and only one correct answer. What is it?

I will post the analysis tomorrow, but you can navigate to the originating site and find the analysis now if you are impatient.

The charm for me of this little gem is that either you see it immediately, or you have to work out the logic. You can get the correct answer either way, but having that sudden flash of insight is special.

After you work it out, go back and look at the post on dice in which A beats B on the average, and B beats C on the average, and C beats A on the average. How are these two puzzles different?

D: All of the above