All about flooble | fun stuff | Get a free chatterbox | Free JavaScript | Avatars    
perplexus dot info

Home > Probability
Marble-Go-Round (Posted on 2004-12-28) Difficulty: 4 of 5
Consider N holes arranged in a circle on a wooden board. A marble is placed in one of them. You toss a fair coin to determine if you should move the marble one hole clockwise or one hole counterclockwise. You keep doing this until the marble has been in each hole at least once.

What is the probability that each of the N holes turns out to be the last hole visited by the marble? Number the holes 1 through N, clockwise starting with the hole in which the marble starts. Obviously the probability for hole 1 is zero, since it already has the marble and there are other holes to visit still.

No Solution Yet Submitted by neshal    
Rating: 3.2000 (5 votes)

Comments: ( Back to comment list | You must be logged in to post comments.)
re(3): solution (spoiler) Comment 4 of 4 |
(In reply to re(2): solution (spoiler) by Charlie)

Thanks for checking Charlie.
  Posted by Hugo on 2005-01-02 20:14:21

Please log in:
Remember me:
Sign up! | Forgot password

Search body:
Forums (0)
Newest Problems
Random Problem
FAQ | About This Site
Site Statistics
New Comments (2)
Unsolved Problems
Top Rated Problems
This month's top
Most Commented On

Copyright © 2002 - 2018 by Animus Pactum Consulting. All rights reserved. Privacy Information