You meet a clever, and dark man. He wants to steal your mind and sell it to the dumbies (an imaginary species of shadows that have an IQ of less than -150)

He offers you to play a game, if you win, he'll give you +50 IQ, but if you lose, he gets 50 of your IQ. It's very tempting, so you listen to the rules and agree.

The rules are as follows:

  • He sets up 3 cups.

  • You have to turn them all upright by turning 2 cups over at a time each turn.

  • You only get 6 turns.

It seems like a fairly easy game, You play him a few times and win, then he offers you the ultimate mind, but if you lose, he takes all if your IQ. Knowing how simple this is, you accept, but here's the trick, you lost!

This evil man tricked you! But how did he do it?

  • 8
    $\begingroup$ Wow, for winning a few times, you sure don't seem to have gotten any smarter if you can't see past his simple trick. I'm kinda skeptical of the man's ability to actually influence your IQ. ;) $\endgroup$ – Rob Watts Oct 29 '14 at 21:07
  • 1
    $\begingroup$ @RobWatts: Second of all, IQ doesn't even work that way. It's not a physical quantity you can give and take from. $\endgroup$ – Joe Z. Oct 30 '14 at 16:34
  • $\begingroup$ It can be taken via death, but not bestowed $\endgroup$ – tox123 Nov 16 '14 at 2:48

He left it with 2 cups upright. By flipping 2 cups at once you can only change this to 2 upright (if you flipped 1 up, 1 down) or 0 upright (if you flipped both of the 'up' cups). Similarly for the 0 upright state you can only get to 0 or 2 upright. It doesn't matter how many turns you have.


You are bested by the limitation on having to flip 2 cups at a time. There is no way to get 3 upright by flipping 2 cups at a time.

If all 3 are down, first flip will set 2 up. After that, you will either have 2 up (flip an up to down, and a down to up) or go back to 3 down.

The man likely tricked you before the final round by having all 3 cups up, or just 1 cup up to start with (I'm assuming the question was about getting all 3 cups up at the end of the 6 steps).

  • $\begingroup$ 1 cup up allows victory at the end of six turns. For each of the first 5 turns, flip 1 up and 1 down. This keeps you in the one cup up state. On the sixth turn flip the two downward cups to win. $\endgroup$ – frodoskywalker Oct 29 '14 at 18:24
  • $\begingroup$ Ah, I was ambiguous on how he tricked you. The 3 or 1 up were the "few times and win". $\endgroup$ – JonTheMon Oct 29 '14 at 18:28

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