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 the numbers are unique to the letters AND duplication is not permitted, then you don't need to tunr over any card, as the hypothesis is already disproved when a 'E' & '4' turn up on the table.

If numbers are unique but duplication is permitted... then turn over either 'E' or '4'

If numbers are not unique, then duplication has to be permitted by default... in that case you just need to turn over 'E'

Posted by Syzygy on 2004-12-15 13:23:56