Tuesday, December 14, 2010

Gift exchange

Bitkidoku proposes this holiday nut. Six friends want to exchange gifts. Each person will buy one gift. To determine who they will give their gift to, they each put their name in a hat and take turns drawing. If a person draws their own name, they put it back and draw again. If the last person draws their own name, they all start over from the beginning.

How many possible outcomes are there?

Friday, December 03, 2010

Four-way word set


The Puzzle Podcast introduced (in episodes 5 and 6) a puzzle called, unaccountably, "GO Mental." Four words are given; three of them follow an unstated rule and one does not. For example:

twin triplet king queen

Which one doesn't fit? The puzzles provide a few seconds of wonderment and a pleasant little flash of recognition.

It occured to me that a good challenge would be to come up with a quartet of words based on four rules, such that each word obeys three rules and violates one. After a year, I came up with this set:

charger colt dolphin mustang

Instead of stating the rules, the solver is encouraged to provide a word that satisfies all four rules. And then to come up with a new quartet in under a year.