Probably not transitive

From Math Puzzle Wiki
Revision as of 19:59, 13 July 2013 by Oscarlevin (talk | contribs)
(diff) ← Older revision | Latest revision (diff) | Newer revision → (diff)
Jump to: navigation, search
Probably not transitive.png

I first heard a similar version of this puzzle on the The Math Factor.

Puzzle

Consider the following card game: the 2 through 10 of spades are placed in three piles of three cards each. Player 1 picks any pile, then player 2 picks one of the remaining piles. Each player picks one of their three cards at random - high card wins. Now in the piles pictured, player 1 has a winning strategy: pick pile A, as any card in that pile would be a winner. But if the cards were arranged differently, things might not be so simple.


Find an arrangement of the cards into three piles so that player 2 has a winning strategy. That is, player 2 can always pick a pile that has a greater than 50% chance of beating the pile picked by player 1. Or prove that this is impossible.