# Same birthday probability Calculator

## Calculates the probability that one or more pairs in a group have the same birthday.

 n persons in a group 6dgt10dgt14dgt18dgt22dgt26dgt30dgt34dgt38dgt42dgt46dgt50dgt Probability with same birthdays p(n) %
 (1) the probability that all birthdays of n persons are different.$\normal \\\vspace{5}\hspace{20}\overline{p}(n)={\large\frac{364}{365}}\times{\large\frac{363}{365}}\times{\large\frac{362}{365}}\times\cdots\\\hspace{50}={\large\frac{365\times364\times363\times\cdots\times(365-n+1)}{365^n}}\\\hspace{50}={\large\frac{365!}{365^n(365-n)!}}\\$(2) the probability that one or more pairs have the same birthday.$\normal\\\vspace{5}\hspace{20}p(n)=1-\overline{p}(n)\\$This calculation ignores the existence of leap years.

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