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?

I would think that if you turned over '7','E', and '4' you would be able to prove or disprove it. If the '7' is turned over and there is an 'E' it is obviously wrong. If the 'E' is turned over and there is something other than a '4' then the theory is wrong. If the '4' is turned over and there is an 'E' it helps verify that it is correct.

Posted by Robyn on 2005-02-23 17:49:35