If there are two boxes. The first has a 100$ bill and a 1$ bill, and the second has two 100$ bills. If I puck a random box and take out a 100$ bill, whaat is the chance of me taking out another 100$ bill?

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I’m honestly stuck. I’ve seen people say 1/2, others 2/3. Something Monty Hall Problem, Bayes Theorem but I’m still confused so here I am.

Edit: I believe you are not allowed to change your box choice on the 2nd “turn” as that would make having two boxes pointless, wouldn’t it?

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Anonymous 0 Comments

There are 4 possible first draws.

The probability that your first draw is a $100 note is 3/4 since 3/4 notes are $100 notes.

If you can change boxes, there’s a 2/3 chance of drawing another $100 note. 2 of the 3 remaining notes are $100, thus, your chance of starting another $100 is 2/3.

If you aren’t allowed to change boxes, that second note is either a $1 or $100 note. The chance that it’s a $100 note is 1/2. However, since you can’t change your box, and you had a probability of 1/2 of choosing the box with two $100 notes, the probability is 1/2.

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