Riddle - The 3 doors?

Question

You are a participant in a quiz. The quizmaster shows you three closed doors. He tells you that behind one of these doors there is a prize, and behind the other two doors there's nothing.

You select one of the doors, but before you open it the quizmaster deliberately picks out a remaining empty door and shows that there is nothing behind it.

The quizmaster offers you a chance to switch doors with the remaining closed door.

Do you stick to your choice? Or will you switch doors?

Answer 1

I'll keep my own, thank you very much.  Well, Did I win?

Answer 2

I switch, because you said he deliberately picks out A remaining empty door, not ONE OF the remaining empty doors.

Edit~darn! mooovin to slow today. Congrats squeevi, have another thumbs up.

Answer 3

I stick to my choice cuz your first instinct is the best  

Answer 4

switch doors because when u start u have a 33% chance that behind each one there is a prize. then when they open on eof the doors that 33 percent goes to the door that wasnt chosen so now the door u chose has  a 33% chance and the other one 66%. so, u switch doors and win A NEWCAR!!!!!

Answer 5

i take it you just watched 21 huh? lol

Answer 6

You should always switch as there is a 2 in 3 chance of getting a prize when you switch, and only a one in three chance of getting nothing.

Please Could I Say Marilyn Vos Savant was Right, If you would look at my Diagram Below, because, out of the 3 times you stick, you will win only once, yet, it you switch, you win 2 of the 3 times. Get it?

Answer 7

The probability of one door(with prize) from three is 1/3 =33.33% success.

The probability of Success for the Quiz master is One door(with prize) from Two remaining doors is 1/2 =50% success rate.

If you combine both or  you select switching the probability  of net result will be 0.3333 X 0.50 =  0.166650 that is = 16.66%success rate.

so better not to switch.

Take only the 33.33% higher success rate!

Thank you for asking.

Answer 8

woah thats either really hard or there is no possible answer

Answer 9

INCORRECT - once the quizmaster reveals that one of the doors has nothing behind it, your odds of winning the prize change from 1 in 3 (33%) to 1 in 2 (50%).  You remove the opened door from the equation, and there are 2 left - the one you picked, and the one he's trying to get you to switch to.

This question was posed to Marilyn Vos Savant, (smartest woman in the world) and she got it wrong too.

Think about this - if you picked one of the doors with no prizes, the quizmaster wouldn't show you the door with the prize, would he?  He'd show you the other blank one...

If you pick door #1, and the prize is behind door #2, he's not going to show you door #2, will he?  He'll show you door #3.

So at the start of the game you had a 1 in 3 chance of picking the right door.  Once one of the non-winning doors is opened, there are 2 left.  You now have a 1 in 2 chance.  

Half of the time you should switch doors, and half of the time you should stick to your first choice.  It's a simple 50/50.

In other words, the quizmaster could be trying to get you to give up the winning door for a non-winning door, or give up the non-winning door for a winning door.  There's no way to know. Those are the only 2 possible scenarios at that point in the game.  So 50%.

EDIT: Apparently Wikipedia says I'm wrong - but they explain it a little better...  I guess your first choice affects the odds involved in your second choice.  Plus what I said is partially right, the host isn't going to show you where the prie is.

If the host KNOWS where the prize is, your odds are better if you switch.  But if the host doesn't know, it's 50/50.

Answer 10

I stick with the first door because unlike my first choice that had only a 33% chance of success, now that he has offered to direct me away from it now stands with a 67% chance of success.

Answer 11

stay with the door  

Answer 12

stick to my choice...