re: I am going to attempt to blow your minds about people and birthdays

You're very very wrong and I have lost the ability to fathom what you think you're arguing. If you have 367 or more people in a room. AT LEAST 2 of them share a birthday, there is no arguing that, it's a fact and you don't even need math. I'm not going to explain it as many already have in this thread. Let me simplify it, if you have 32 people in a room, at least 2 of them will have the same birth day number of the month. If you have 8 people in a room at least two of them will have been born on the same day of the week. If you have 25 people in a room at leaf two of them will have been born at the same hour in the day. If you have 118 people in a room (accounting for oldest living person at 116 and a newborn baby) at least two of them will have been born in the same year. 13 people guarantees at least two in the same month.

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Is it possible. Yes it is possible.

I would agree that practically speaking, it is impossible, but statistically speaking there is a chance.

What are the odds that no one shares a birthday out of 10 people? out of 100? out of 1,000 or 100,000?

Each of those numbers have a statistical probability that no one will share a birthday. You tell me when that probability hits zero. What is the number?

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You're really not getting this?

Think of it this way. How many rolls of a die does it take to get 100% certainty that there will be a repeat? We would say 7 because the first 6 could be unique but the 7th will have to be one of the 6 that were already rolled.

In the birthday example, think of one person walking into the room at a time, then announcing his or her birthday until there is a repeat. If the first 366 individuals had unique birthdays, every possible birthday would be accounted for. So the 367th person has to result in a repeat.

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That's obvious. What's crazy about this problem is at 70 people it's at 99.9% but it takes until 367 to get to 100%!

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Yeah when I learned about it a probability course, I found it quite counter-intuitive. I had to think of it similar to my edited post with individuals walking into a room announcing their birthdays until there is a match. The second person in a room has one possible match but the third has two possible matches and slightly higher probability of matching. As this rises cumulatively we quickly get to 99%. Still seems crazy though when I don't think it through.