Puzzle - which door?

[Stewart]

I can't remember what was being argued about in this thread from the Dark Ages, but whatever it was, I was right.

[streetster]

No such thing as chance so your all wrong. If you have 2 doors, gold behind door 1 and a steamy turd behind the other most people would want the gold yes ?

If you get 2 goes at this then you would think you have a 50/50 chance of gold with each go. But if you get gold both times then those statistics were wrong. You didn't have a 50/50 chance you had a 100% chance.

... thats like saying if i buy a lottery ticket for the friday draw and win i had a 100% chance of winning, which is clearly wrong.

you could've had 2 goes at opening the doors (assuming you cant just open both doors lol) and ended up with a steaming turd twice. that doesnt mean you had a 0% chance of winning... just that you are unlucky

[Pyrii]

The puzzle doesn't work with 2 doors anyway.

[JK Ferret]

That one's quite easy though - donor sperm?

I thought it was over the midnight period? Because '80 was a leap year, bit harsh to only have a birthday every 4 years, so they shifted along a few minutes

Obviously

I can't remember what was being argued about in this thread from the Dark Ages, but whatever it was, I was right.

First suspicions when I saw Iain 1) posting in a thread, not seen that for yonks, 2) being referred to as Az, his old HEXUS nick. I really should look at the dates more :/

And yoo wuz rong

[Zsev]

Here's an alternative explanation that may help


You are on a game show and are asked to pick between three doors. Behind one of the doors is a million-dollar prize, behind the other two is either a date with Linda Tripp (for the boys) or Ken Starr (for the girls). I am the host and I know what is behind each door and will obviously try to keep you from winning.
I ask you to choose a door and, let’s say, you choose Door #2. Now, I open Door #1, revealing none other than Ken Starr. At this point, I ask if you would like to switch your choice. Here is the question:

1. Is it better to switch?
2. Is it better to stay with your original choice?
3. Does it make a difference in your ability to win?

If you are similar to 99.99% of the sapient human populace, you’ve chosen either the second or third option. So dust off the microphone and dark glasses, baby — you’re off on a date with Linda Tripp.

Yes, it’s hard to take, but it’s true — the best choice is to switch. Think about it. Do the math:

1. The prize is behind Door #3. You first choose Door #2 and so I open Door #1 (I will certainly never open the door with the prize behind it). Out pops Ken Starr. If you stay with Door #2, you lose, if you switch to Door #3, you win.
2. The prize is behind Door #1. You first choose Door #2. I know where the prize is, so this time I open Door #3. Out pops Linda Tripp. If you stay with Door #2, you lose, if you switch to Door #1, you win.
3. The prize is behind Door #2. You first choose Door #2. I know where the prize is, so I open either Door #1 or #3. If you stay with Door #2, you win, if you switch, you lose.

Result? If you switch, you win two out of three times. If you stay, you win one out of three times.

I've heard about this puzzle from a black jack movie, 24 i think ? Couldn't figure it out then but your explanation makes it crystal clear ! THX !

[Stewart]

And yoo wuz rong

2 doors, 1 pick - 50%

Mathimatically that has to be correct, God intended it to be as such.

Not that I can remember exactly what was going on. Something about doors and a prize...

[togoodtobetrue]

... thats like saying if i buy a lottery ticket for the friday draw and win i had a 100% chance of winning, which is clearly wrong.

you could've had 2 goes at opening the doors (assuming you cant just open both doors lol) and ended up with a steaming turd twice. that doesnt mean you had a 0% chance of winning... just that you are unlucky

If you won the lottery how much of it did you win ? 100% ? if you could rewind time and go back to the time before you won the lottery what chance would you have of winning ? :-P

[togoodtobetrue]

There are 2 doors behind 1 door is safety behind the other is certain death. There's 2 guards 1 on each door 1 guard always lies the other always tells the truth, you can ask 1 question in order to reach safety what question do you ask ?

[Zathras]

"Which door would the other guard say is the door to safety?" Then choose the other door.

[mightymouse]

haven't read to the last post but i will select to switch feels like the right thing to do

[NeedMoarFarms]

I actually understand this a little, but I'm finding it hurt to put it into words:

When you first choose, the probablity of choosing the right door is 1/2. When another door is opened, the probability that you choose the right door is still 1/3, amd the probablity that the other door is right is 2/3. If you choose to switch 3 times, 2 times you would be right. If you stuck with your door, you would loose 2 times and be right once. You are twice as likely to get the prize if you switch.