25/366
365 + leap year
find the probability that of 25 randomly selected people, atleast two share the same birthday
2 answers
one minus this probability is the probability that everyone has a different birthday. The first selected person has a certian birthday, the second person has a probability of 364/365 of havng a different birthday, the third person has a probability of 363/365, etc. Multiply all the probabilities together and subtract from 1.
1 answer