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

Home > Probability
Fifty-Fifty Again? (Posted on 2017-06-14) Difficulty: 3 of 5
I have three coins, like the coins from Fifty-fifty. The first coin is a regular coin with heads and tails sides; the second coin has heads on both sides; the third coin has tails on both sides.

Two coins are chosen and flipped, with the third still shrouded in a pouch. The results of the flips shows one head and one tail. What is the probability that the normal coin is the coin still in the pouch?

See The Solution Submitted by Brian Smith    
Rating: 3.0000 (1 votes)

Comments: ( Back to comment list | You must be logged in to post comments.)
re: Solution (spoiler) Comment 3 of 3 |
(In reply to Solution (spoiler) by Steve Herman)

Baye is always right (although not always easy to see).

With good coin in purse, there are four combinations (out of four) that will produce [H/T].  With good coin on table, there are four combinations (out of eight) that will produce [H/T].

Well done, Mr. Herman.

  Posted by hoodat on 2017-06-15 12:46:35

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


Search:
Search body:
Forums (0)
Newest Problems
Random Problem
FAQ | About This Site
Site Statistics
New Comments (4)
Unsolved Problems
Top Rated Problems
This month's top
Most Commented On

Chatterbox:
Copyright © 2002 - 2017 by Animus Pactum Consulting. All rights reserved. Privacy Information