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?

Question

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?

In: 10

Answer 1

Chance for each individual bill: 25%

Chance for picking a $100 bill: 75%

Chance for the $100 bill to come from the 200 box: 50%

Chance for the $100 bill to come from the 101 box: 25%

50%/75% to 25%/75%

-> 2/3 to 1/3 chance for the other bill to also be a $100 bill