[d20] What don't you know? (free pdf books)

[Hussar]

Cool beans. Have to keep checking this one. Bloody time diference. Grumble, grr.

 

[Romnipotent]

if I didn't already have most of the stuff... Heh

 

[TheLe]

[imager]http://www.thele.com/thelegames/images/html/quiz.gif[/imager]New Quiz! First person to post a correct answer wins a free pdf book (see original post). Previous winner is not eligable for this prize.

Quiz:
Before you is an elder Dragon, who knows of your quest (and can wipe you out with a sneeze). It shows you 3 unopened doors and says, "Behind 1 of these doors is the artifact you seek. Behind 2 of these doors you will find death and eternal hell for all your souls (no save). Choose wisely".

Now, let's say you choose a door, but do NOT open it.

The Dragon senses your hesitation and says to you, "There are 2 unopened doors that you have not chosen. Of these, I will open 1 of them to show you the death you have avoided." True to it's word, the Dragon opens 1 of the unopened doors showing death (which suspsiciously looks like Lorraine Williams). There are now only 2 unopened doors left -- the door that you chose, and the door that the Dragon did not open.

The Dragon continues, "The Artifact is behind one of the unopened doors. You now have a choice. You may keep the unopened door that you have chosen, or you can switch to this last unopened door. Choose wisely."

Question 1: Do you keep the original door you choose, or do you switch to the other unopened door?

Question 2: What is the probability that the original door you choose has the artifact, and what is the probability that the other unopened door has the artifact?

You must correctly answer both questions to win this quiz.

THE LE GAMES - WE ENHANCE WORLDS

 

[Pinotage]

1) Switch to the other door.

2) 1/3 to gain the artifact on the original choice, 2/3 to gain the artifact on switching to the other door after the dragon's choice.

Pinotage

 

[Angel Tarragon]

[imager]Question 1: Do you keep the original door you choose, or do you switch to the other unopened door?

Question 2: What is the probability that the original door you choose has the artifact, and what is the probability that the other unopened door has the artifact?

1) original door
2) 50 % / 50%

 

[Psion]

Does this dragon look like Monty Hall?

 

[Belmont20xx]

You switch. As it is, there is a 1/3 chance you have the right door. By switching, you receive a 2/3 chance of the right door I believe.

 

[Wystan]

1. Personal Preference.... (explain): The Dragon Sensing your hesitation is showing you the third option. Therefore making the remaining 2 doors equal. Choose what you will. 50% chance that either is wrong.

2. See #1

(Optional Answer based on it being a Dragon)

1. Keep your door, he is trying to trick you into selecting the second door.
2. This is a Dragon, he does not want to give you any treasure, He is tempting you to change doors as there is a 100% chance it is behind the door you selected.

 

[Psion]

1) Switch to the other door.

2) 1/3 to gain the artifact on the original choice, 2/3 to gain the artifact on switching to the other door after the dragon's choice.

What does he win, Jay?

 

[TheLe]

1) Switch to the other door.

2) 1/3 to gain the artifact on the original choice, 2/3 to gain the artifact on switching to the other door after the dragon's choice.

Pinotage

Damn that was quick. Pinotage, email your winning selection, and I will have rpgnow.com fire it off to you. Congrats. (Pino was the first to correctly answer)

You see, when you first choose the door, it is based on 3 choices, so whatever you choose, it is a 33% chance of being correct. And there is a 66% chance that the artifact is in one of the other two doors.

So, once the dragon shows you death in one of the other doors, it still does not change the probability. Your door still has a 33% probability of having the artifact, while there is still a 66% probability that the artifact is behind one of the other two doors. The dragon exposing one of the doors does not change that.

Therefore the correct answer is to switch doors, which now gives you a 66% probability of having the correct door.

Want proof? Grab a friend and do it with 100 doors. Let him choose 1, eliminate 98 death doors, and give him a choice to keep his door or switch to the last unopened door. You will find the artifact in the last unopened door 99% of the time. (it is NOT 50/50). Then you will see the light.

Yes, this is known as "The Monty Hall Paradox"

Good work Pinotage.

~Le