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
- - - - -

3 Doors and 2 Goats


  • Please log in to reply
6 replies to this topic

#1 jamie bickers

jamie bickers

    Newbie

  • Members
  • Pip
  • 6 posts

Posted 08 January 2008 - 09:01 PM

You are on a game show and there are three doors. The presenter tells you that behind one of doors there is a car and behind the other two are goats, if you pick the car you win it. After you have picked a door the presenter opens a different door with a goat behind it, he then gives you the chance to change what door you open, what should you do?

Hint: It is not 1/2 as you would first think.
Spoiler for Simple proof

  • 0

#2 Writersblock

Writersblock

    Senior Member

  • Members
  • PipPipPipPip
  • 597 posts

Posted 08 January 2008 - 09:13 PM

You are on a game show and there are three doors. The presenter tells you that behind one of doors there is a car and behind the other two are goats, if you pick the car you win it. After you have picked a door the presenter opens a different door with a goat behind it, he then gives you the chance to change what door you open, what should you do?


Not sure what you mean by "what should you do?"
There's been another post on here (as I rememeber) that had a similar question and it was established that you have a 2/3 shot at getting it right, but are you asking whether changing doors will affect those odds?
  • 0

#3 jamie bickers

jamie bickers

    Newbie

  • Members
  • Pip
  • 6 posts

Posted 08 January 2008 - 09:19 PM

I mean what should you do so that you have the highest chance of getting the car?
  • 0

#4 bonanova

bonanova

    bonanova

  • Moderator
  • PipPipPipPip
  • 5918 posts
  • Gender:Male
  • Location:New York

Posted 08 January 2008 - 09:41 PM

This is a classic puzzle, most recognizably called the Monty Hall problem.
It's been posted elsewhere in this discussion board.
Spoiler for -- The answer is --

  • 0
The greatest challenge to any thinker is stating the problem in a way that will allow a solution.
- Bertrand Russell

#5 roolstar

roolstar

    Advanced Member

  • Members
  • PipPipPip
  • 250 posts
  • Gender:Male

Posted 10 January 2008 - 10:47 AM

Hey Jamie,

That's a very interesting puzzle you have there...

And I can also provide you with an interesting twist...

Just visit the discussion board these guys mentioned...

Death Probability! Really Hard One!
  • 0

#6 Martini

Martini

    Senior Member

  • Members
  • PipPipPipPip
  • 770 posts

Posted 10 January 2008 - 02:43 PM

Welcome to the boards, jamie.

This riddle has already been posted and can be found here. Any further discussion can continue in that thread, so I'm going to close this one. Don't let that discourage you from posting other riddles, though.

If anyone wanting to post a riddle isn't sure if it's been discussed here before, just use the search feature for key words. For instance, for this riddle, a search for "goat" will come up positive. Thanks.
  • 0

#7 bhramarraj

bhramarraj

    Advanced Member

  • Members
  • PipPipPip
  • 254 posts

Posted 13 September 2012 - 08:13 AM

Say you are given a heap of 50 coins, in which only one coin is real, while all other coins are fake. you can not recognize the fake or real coin by seeing or touching them.
When you grab a coin from the heap of 50 coins, there was only one out of 50 chances that you grabed right coin.
Suppose the host now removes 47 fake coins. Only two coins are left in the heap and one in your hand. Now what you will do?
Stick to the coin which you selected When there were 50 coins and there was only a very remote chance that the coin selected was real...?
OR
You will leave that and grabe another coin....?

Definitely when you do not know which coin is real, you shall like to leave the coin in hand which had more chances to have been fake, and grab a new coin which has now better chances to be real.
  • 0




0 user(s) are reading this topic

0 members, 0 guests, 0 anonymous users