Only people with an IQ of 115 or higher can get this right

[Hitman928]

As posted in the OP. you're picking from the same box where you got the gold ball from. You don't know what the other ball is, it's either gold or silver.

If you had the choice between the 2 boxes (which in the OP is not the scenario), of course the correct answer would be 2/3.

Related threads/articles.
https://en.wikipedia.org/wiki/Bertrand's_box_paradox
https://whyevolutionistrue.wordpress.com/2018/02/20/the-answer-is-2-3/
http://datagenetics.com/blog/june72013/index.html

The answer to the question in the OP is 2/3.

 

[paperfist]

The answer to the question in the OP is 2/3.

How can it be 2/3 when you can only pull from 1 box which only has 1 ball left?

Clearly this is a multiple choice question in which Mayne left out part of the screen shot.

 

[Mayne]

I wouldn't do something like that.

 

[brianmanahan]

Clearly this is a multiple choice question in which Mayne left out part of the screen shot.

maybe that's why they banned him at mmo

 

[Humpy]

However, we are ignoring the occurrences of when a S is picked first but it is still a part of the probability system.

We are ignoring the occurrences of when an S is picked first becasue we were told that gold was picked. Then we are asked for the probability of what happens next.

You are answering a different question.

 

[bigboxes]

We are ignoring the occurrences of when an S is picked first becasue we were told that gold was picked. Then we are asked for the probability of what happens next.

You are answering a different question.

Reading comprehension eludes many people in this thread.

 

[Hitman928]

We are ignoring the occurrences of when an S is picked first becasue we were told that gold was picked. Then we are asked for the probability of what happens next.

You are answering a different question.

No, I'm answering the exact right question. The probability still must be taken into account even though we are ignoring the actual occurrence. Do you think it is 2/3 or 1/2?

 

[brianmanahan]

We are ignoring the occurrences of when an S is picked first becasue we were told that gold was picked. Then we are asked for the probability of what happens next.

You are answering a different question.

even though gold was picked, the box with 2 golds in it was twice as likely to be picked as the box with 1 gold and 1 silver in it

 

[Humpy]

The probability still must be taken into account even though we are ignoring the actual occurrence.

Why?

I think you are giving the probability of two picks when we are only asked about one?

 

[hasu]

Let us try an exaggerated version. I am going with the exact version of the question as in the first post.

I have 10 boxes each with two coins as shown below (G for Gold and S for Silver):

[GG] [SS] [SS] [SS] [SS] [SS] [SS] [SS] [SS] [SS]

Someone picked one coin from a box and found that it was Gold.
What is the chance that the next coin if picked from the same box be Gold?

 

[Darwin333]

Conditions of the test already stated you drew a gold ball, you cannot rewrite the conditions.

He isn't rewriting the conditions. If you pull a gold ball you are more likely to have pulled it from the box with only gold balls. If you pulled a silver ball you are more likely to have pulled it from the box only silver balls. This information must be considered in future questions which is why the answer is 2/3.

 

[mindless1]

Bertrand was wrong. There is no probability factor mitigating the 50% chance after the first box and coin was chosen because at that point the probability of the first move was established at 100%. The way a question is asked, matters.

 

[Humpy]

Some people are giving an answer to the question (from the wikipedia link) of probability that "after choosing a box at random and withdrawing one coin at random, if that happens to be a gold coin, of the next coin drawn from the same box also being a gold coin." The probability of that string of events has been shown to be 2/3.

The question in the OP is different.

 

[brianmanahan]

i think we need to ban mayne, just to be sure

 

[GoodRevrnd]

i think we need to ban mayne, just to be sure

4 f'n pages to get to the correct answer...

 

[Humpy]

i think we need to ban mayne, just to be sure

Can't you write some sort of AI computer program thingy that randomly bans Mayne for a few seconds every minute?

Something frustrating enough that drives him to spiral even deeper into depression and alcoholism?

 

[brianmanahan]

4 f'n pages to get to the correct answer...

at least that's 10x less pages than it took the mmo forum to ban him

which means we're 10x as smart

 

[brianmanahan]

Can't you write some sort of AI computer program thingy that randomly bans Mayne for a few seconds every minute?

Something frustrating enough that drives him to spiral even deeper into depression and alcoholism?

i would, but he'd probably strangle me

 

[Humpy]

i would, but he'd probably strangle me

Defense against Full Nelson Anal is difficult but not impossible.

 

[Hitman928]

Bertrand was wrong. There is no probability factor mitigating the 50% chance after the first box and coin was chosen because at that point the probability of the first move was established at 100%. The way a question is asked, matters.

This doesn't make sense. The setup of the question is why the probability is 2/3. As soon as you know you have a gold coin as the first choice, the probability is 2/3. Again, if you're so sure that the probability is 50%, why does the actual experimental data disagree with you? Is there experimental data showing it's 50%?

 

[Hitman928]

Let us try an exaggerated version. I am going with the exact version of the question as in the first post.

I have 10 boxes each with two coins as shown below (G for Gold and S for Silver):

[GG] [SS] [SS] [SS] [SS] [SS] [SS] [SS] [SS] [SS]

Someone picked one coin from a box and found that it was Gold.
What is the chance that the next coin if picked from the same box be Gold?

I like where you're going but I think it simplifies it too much, it becomes almost like the trivial solution. I prefer to exaggerate it this way.

[G-G-G-G-G-G-G-G-G-G-G-G-G-G-G-G] [G-S-S-S-S-S-S-S-S-S-S-S-S-S-S-S]

If I told you I picked a box and coin at random and that it was a gold coin, which box which you guess it came from? If you say the first box, then you should agree that the answer to the OP is 2/3. If you say it's 50/50, I have no idea how to help you, lol.

 

[paperfist]

I wouldn't do something like that.

You ah didn't eat the answer, right Mayne?

 

[Slew Foot]

This doesn't make sense. The setup of the question is why the probability is 2/3. As soon as you know you have a gold coin as the first choice, the probability is 2/3. Again, if you're so sure that the probability is 50%, why does the actual experimental data disagree with you? Is there experimental data showing it's 50%?

The experiment is done incorrectly because it factored in occurrences where the first ball picked was silver. We are told the the first ball picked is Gold, so we are free to ignore all the instances where the first ball is silver, since the questions being asked is "what is the probability of a second gold being drawn, after a first gold has already been drawn"

 

[brianmanahan]

The experiment is done incorrectly because it factored in occurrences where the first ball picked was silver. We are told the the first ball picked is Gold, so we are free to ignore all the instances where the first ball is silver, since the questions being asked is "what is the probability of a second gold being drawn, after a first gold has already been drawn"

even if you ignore occurrences where the first ball picked was silver, you were still 2x as likely to have picked the box with 2 gold balls as your first choice than the box with 1 gold + 1 silver

 

[destrekor]

There are more than enough tortured explanations in this thread to make my head hurt for days. Thanks y'all.