Jump to content


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
 

Photo
- - - - -


  • Please log in to reply
27 replies to this topic

#1 bushindo

bushindo

    Senior Member

  • VIP
  • PipPipPipPip
  • 721 posts
  • Gender:Male
  • Location:Los Angeles, CA

Posted 04 June 2009 - 09:30 PM

I promised final and adiace a break after their exemplary effort on Prisoner on a death row 8. Well, break's over.

There are 5 prisoners on a death row, call them A, B, C, D, and E. The warden gives them a chance to live. He gives them each a doctored gun and let them engage in a death match. Let's say the guns are modified so that their chances of hitting varies. A's chance of hitting and killing any other player is always 4/20. B's chance is always 7/20, C's is 10/20, D's is 13/20, and E's is 16/20. Assume that every single shot will either miss or kill.

The players shoot in this order, A, B, C, D, and E. Unlike Prisoners on a death row 8, prisoners don't have a choice of shooting anyone they want. Everyone must shoot someone right after him in the sequence. For example, A must shoot B, and if B is already dead, A must shoot C if C is alive, or go on to the next person if C is dead too. The person last in the sequence must shoot someone at the start of the sequence. So for instance, let's say it's E's turn, he must shoot A, or the next alive person at the start of the sequence if A's dead. The game continues until there's only 1 person left. The last person standing earns his freedom.

The warden likes you, so the night before the game he allows you to pick your position as A, B, C, D, or E.

1) What position should you pick?

Super hard bonus: What is the exact chance of survival for A, B, C, D, and E. Any method is allowed, but probabilistic method like simulation is not allowed since simulation provides an estimate of the rate but not the exact numbers. I'm not after the numbers, though. I'm looking for methods that would allow us us to compute the exact chance of survival. You don't have to implement the method, but you must describe it, and it must be doable within a reasonable amount of time.

Edited by bushindo, 04 June 2009 - 09:33 PM.

  • 0

#2 perk8504

perk8504

    Junior Member

  • Members
  • PipPip
  • 24 posts

Posted 04 June 2009 - 10:04 PM

My gut feeling is wanting to be C, gut with some real quick mental run downs of scenarios, but will need some time for the bonus and actually figuring out an answer I am confident in for picking the position too.
  • 0

#3 icepick1346

icepick1346

    Newbie

  • Members
  • Pip
  • 11 posts

Posted 04 June 2009 - 10:06 PM

My gut feeling is wanting to be C, gut with some real quick mental run downs of scenarios, but will need some time for the bonus and actually figuring out an answer I am confident in for picking the position too.


I agree, but I won't be able to work the math till I get home later...
  • 0

#4 adiace

adiace

    Advanced Member

  • Members
  • PipPipPip
  • 113 posts

Posted 04 June 2009 - 11:15 PM

Spoiler for I would choose

Edited by adiace, 04 June 2009 - 11:20 PM.

  • 0

#5 adiace

adiace

    Advanced Member

  • Members
  • PipPipPip
  • 113 posts

Posted 04 June 2009 - 11:31 PM

Spoiler for I would choose

Spoiler for oops

  • 0

#6 adiace

adiace

    Advanced Member

  • Members
  • PipPipPip
  • 113 posts

Posted 05 June 2009 - 12:05 AM

Spoiler for oops

Spoiler for back to

Edited by adiace, 05 June 2009 - 12:06 AM.

  • 0

#7 final

final

    Advanced Member

  • Members
  • PipPipPip
  • 271 posts

Posted 05 June 2009 - 12:31 AM

Spoiler for um

  • 0

#8 James8421

James8421

    Advanced Member

  • Members
  • PipPipPip
  • 468 posts

Posted 05 June 2009 - 12:32 AM

Spoiler for for part 1..



Spoiler for super hard part..

  • 0

#9 adiace

adiace

    Advanced Member

  • Members
  • PipPipPip
  • 113 posts

Posted 05 June 2009 - 12:37 AM

Spoiler for Damn i keep flip floping

  • 0

#10 adiace

adiace

    Advanced Member

  • Members
  • PipPipPip
  • 113 posts

Posted 05 June 2009 - 01:12 AM

Spoiler for Damn i keep flip floping

Spoiler for part 1

Edited by adiace, 05 June 2009 - 01:12 AM.

  • 0




0 user(s) are reading this topic

0 members, 0 guests, 0 anonymous users