## 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

# Comparing gambling systems

49 replies to this topic

Senior Member

• Members
• 1837 posts
• Gender:Female

Posted 18 November 2013 - 06:03 PM

Consider a gambling machine A. When you put in \$X and pull the handle, it will spit out (equally likely) either \$0.7*X, \$0.8*X, \$0.9*X, \$1.1*X, \$1.2*X, or \$1.5*X.

Now consider the following two ways of playing this machine:

Put in \$1, pull the handle, and keep whatever you get. Repeat.
Initially, put in \$1. Pull the handle, then put in whatever you get. Repeat.
Can you win money with this machine? Which is the better way to play? How can this be?

• 0

### #2 bonanova

bonanova

bonanova

• Moderator
• 6157 posts
• Gender:Male
• Location:New York

Posted 18 November 2013 - 07:13 PM

Spoiler for Looks like

• 0

Vidi vici veni.

### #3 Prime

Prime

Senior Member

• Members
• 872 posts
• Gender:Male
• Location:Illinois, US

Posted 18 November 2013 - 09:07 PM

Spoiler for seems straightforward

Edited by Prime, 18 November 2013 - 09:14 PM.

• 0

Past prime, actually.

### #4 plainglazed

plainglazed

Abuse of PoWers

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

Posted 18 November 2013 - 09:25 PM

I really should know better than to chime in here -

Spoiler for less than proud and surely too simple

EDIT:  I knew I shouldn't have tried to play with the big boys.  See where I erred now and am with Prime.

• 0

### #5 bonanova

bonanova

bonanova

• Moderator
• 6157 posts
• Gender:Male
• Location:New York

Posted 19 November 2013 - 08:44 AM

Spoiler for Not convinced

• 0

Vidi vici veni.

### #6 phil1882

phil1882

Senior Member

• Members
• 564 posts

Posted 19 November 2013 - 11:36 AM

hmmm

Spoiler for

• 0

### #7 bonanova

bonanova

bonanova

• Moderator
• 6157 posts
• Gender:Male
• Location:New York

Posted 20 November 2013 - 09:50 AM

hmmm

Spoiler for

Spoiler for Understanding Method 2

• 0

Vidi vici veni.

### #8 Rainman

Rainman

• Members
• 161 posts

Posted 20 November 2013 - 06:06 PM

Spoiler for what is expected

• 0

Senior Member

• Members
• 1837 posts
• Gender:Female

Posted 20 November 2013 - 06:12 PM

I temporarily changed this to unsolved to consider Rainman's thorough argument.  Anyone else have thoughts?

• 0

### #10 Prime

Prime

Senior Member

• Members
• 872 posts
• Gender:Male
• Location:Illinois, US

Posted 20 November 2013 - 07:47 PM

I temporarily changed this to unsolved to consider Rainman's thorough argument.  Anyone else have thoughts?

Change it back. The proof is coming.

• 0

Past prime, actually.

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

0 members, 0 guests, 0 anonymous users