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?

If a letter or number can appear more than once on the four cards, then you must flip over the 'E' card and the '4' card.

If a letter or number may only appear once on any of the given four cards, then you wouldn't have to flip over any of the four cards because both the 'E' and the '4' appear in the selection.

Posted by artemis on 2005-03-05 17:00:38