I present to you a deck of 4 cards. Each card has on one side a letter of the alphabet, and on the other side a single digit from 0-9.

I propose a hypothesis that may apply to this deck:
If the letter is 'E', then the number on the other side is '4'.

I then drop the 4 cards on the table, and you see: 'B', '7', 'E', '4' (on the respective cards).

Which of the 4 cards must you turn over to verify or disprove my hypothesis?

excuse me, for i have not read all of the related posts.  you can turn over the card on which you see an 'E,' and if it has a '4' on the other side, the hypothesis is supported.  you need not turn over the card on which you see a '4,' because the hypothesis did not state a requirement for such a condition.  in order to prove the hypothesis, though, you need to turn over the '7' card; if it has an 'E' on it, the hypothesis has been disproven.  if not, it has been proven.

Posted by brad on 2005-03-29 21:07:48