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Author(s) -
John McGee
Publication year - 1960
Publication title -
journal of the american oil chemists' society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.512
H-Index - 117
eISSN - 1558-9331
pISSN - 0003-021X
DOI - 10.1007/bf02982104
Subject(s) - citation , computer science , information retrieval , world wide web , library science
Suppose that there are n people in a room. What is the exact probability that there are exactly two people (A,B) such that A and B have the same birthday and no others share a birthday? Note that this is a variation of the famous birthday paradox where the question is to determine the probability that at least two of n people have the same birthday. Determine the probability for n=5 as an exact fraction. Give a decimal approximation for n=30. Then give a formula for the general case for any n>2. Challenge: Extend the problem for two distinct pairs (A,B), (C,D) such that A,B share a birthday, and C,D share a different birthday and everyone else has a distinct birthday.