The Grey Labyrinth is a collection of puzzles, riddles, mind games, paradoxes and other intellectually challenging diversions. Related topics: puzzle games, logic puzzles, lateral thinking puzzles, philosophy, mind benders, brain teasers, word problems, conundrums, 3d puzzles, spatial reasoning, intelligence tests, mathematical diversions, paradoxes, physics problems, reasoning, math, science.

Ghost Post · Icarian Member

Probability is a way of quantifying likelihood. If something has already happened, the term "likelihood" becomes meaningless. Once the coin has been tossed, and the outcome is determined, there is no probability. There is, however, probability (likelihood) of being correct when guessing. So even though the probability of heads is 1/2 before the toss, the probability of guessing correct by saying tails is 1/3 after the toss. They are two different issues and the puzzle was posed in a way (intentionally) that would mix those two up and create a paradox.
(I didn't mean to start a new topic. I just registered and wasn't sure how this worked)

[This message has been edited by Duck (edited 10-07-1999).]

Ghost Post · Icarian Member

Makes sense to me. I wonder if anyone else sees it that way.