Question :
What is the probability that atleast two out of n persons have the same birthday ? Assume 365 days in a year and all days are equally likely
Pr(at least 2) = 1 - Pr(None) - Pr(1).
Now read this: Birthday problem - Wikipedia, the free encyclopedia
In the eq provided
Pr(at least 2) = 1 - Pr(None) - Pr(1).
1 - Pr(None) = Pr of all having the same Bday
Pr(1) = Pr of 1 having the same Bday
am i correct!!! then how is
(Pr of all having the same Bday) - (Pr of 1 having the same Bday) = (Pr of atleast 2)
please explain me i am dum!!!!!