## Welcome to BrainDen.com - Brain Teasers Forum

 Welcome to BrainDen.com - Brain Teasers Forum. Like most online communities you must register to post in our community, but don't worry this is a simple free process. To be a part of BrainDen Forums you may create a new account or sign in if you already have an account. As a member you could start new topics, reply to others, subscribe to topics/forums to get automatic updates, get your own profile and make new friends. Of course, you can also enjoy our collection of amazing optical illusions and cool math games. If you like our site, you may support us by simply clicking Google "+1" or Facebook "Like" buttons at the top. If you have a website, we would appreciate a little link to BrainDen. Thanks and enjoy the Den :-)
Guest Message by DevFuse

# Infinite Flips

Best Answer bonanova, 11 December 2013 - 06:40 PM

Spoiler for Suggestive proof

Go to the full post

23 replies to this topic

Senior Member

• Members
• 1837 posts
• Gender:Female

Posted 04 December 2013 - 02:24 AM

Given a coin with probability p of landing on heads after a flip, what is the probability that the number of heads will ever equal the number of tails assuming an infinite number of flips?

• -1

### #2 bonanova

bonanova

bonanova

• Moderator
• 6161 posts
• Gender:Male
• Location:New York

Posted 05 December 2013 - 08:09 AM

Spoiler for For starters

Edited by bonanova, 07 December 2013 - 10:51 AM.
Replacing first guess with solution

• 0

Vidi vici veni.

### #3 plainglazed

plainglazed

Abuse of PoWers

• Moderator
• 4762 posts
• Gender:Male
• Location:nc us

Posted 05 December 2013 - 06:24 PM

Spoiler for I should know better...

• 0

### #4 bonanova

bonanova

bonanova

• Moderator
• 6161 posts
• Gender:Male
• Location:New York

Posted 07 December 2013 - 10:52 AM

On further thought, I think my answer gives only a lower bound.

• 0

Vidi vici veni.

### #5 bonanova

bonanova

bonanova

• Moderator
• 6161 posts
• Gender:Male
• Location:New York

Posted 07 December 2013 - 02:58 PM

• 0

Vidi vici veni.

### #6 plainglazed

plainglazed

Abuse of PoWers

• Moderator
• 4762 posts
• Gender:Male
• Location:nc us

Posted 07 December 2013 - 04:14 PM

Spoiler for a question for bonanova

• 0

### #7 bonanova

bonanova

bonanova

• Moderator
• 6161 posts
• Gender:Male
• Location:New York

Posted 07 December 2013 - 04:31 PM

Spoiler for a question for bonanova

Spoiler for Thats right

• 0

Vidi vici veni.

Senior Member

• Members
• 1837 posts
• Gender:Female

Posted 07 December 2013 - 04:33 PM

Spoiler for edit--forgot spoiler

Edited by BMAD, 07 December 2013 - 04:33 PM.

• 0

### #9 plainglazed

plainglazed

Abuse of PoWers

• Moderator
• 4762 posts
• Gender:Male
• Location:nc us

Posted 07 December 2013 - 04:44 PM

@ bonanova - but infinity flips is a fair many more than "a large number of flips"

@ BMAD - someone but not everyone?

hopefully my responses here are taken as meant to be - lack of full comprehension of very large numbers - and not as deviating from the spirit of the riddle.

• 0

Senior Member

• Members
• 1837 posts
• Gender:Female

Posted 07 December 2013 - 05:09 PM

It depends on how you splice the question.  essentially we could have one person play 1,000,000 and they will have a low but existing probability of being even.  We could also have 500,000 people play twice and have again a low but existing probability of being even.

• 0

#### 0 user(s) are reading this topic

0 members, 0 guests, 0 anonymous users