This information is false. If there's 23 people in a room...all with a different birthday. And i walk in the room..the odds of me having the same bday as anyone in there..is 23/365...which is roughly6%
that's not how statistics work! you're disregarding the exponential aspect of it, as well as assuming that only YOUR birthday is relevant. don't forget there are 23 other people in the room! if we're talking about the probability of one of the 23 people sharing just *YOUR* birthday that's a completely different statistic (as evidenced by this thread!) however, the statistic cited - out of 23 people in a room, there's a 50% chance of two sharing a birthday - is completely true and discussed often in statistic and other mathematic classes because it's considered a "paradox" (in reality it's just people misunderstanding nonlinear probability!) just like there's an exponential decrease in the odds of say, rolling a 1 on a dice a certain # of times in a row - that is to say, if you want to roll a 1 two times in a row instead of just 1 time, it's not 50% less likely as you might expect - it's actually 6x less likely. there's a 1/6th chance of getting the first 1 - but there's a 1/36 chance of both being a 1 since it's now (1/6)*(1/6) the birthday paradox works much the same way! the increase in probability of someone sharing a birthday with one of the current people in the room increases exponentially, NOT linearally, with each added person (23*22)/2 = 253 "pairs" between people in the room. the odds of every single one of those pairs NOT being a match is 49% - just under half. meaning there's a 51% chance that two of the people DO match ? #math.