Exercise 3.1

Answers

If the k-th person’s arrival results in the first birthday match, the first k 1 people have 365 364 (365 k + 2) choices of birthday assignments such that no two people have the same birthday. The k-th person has k 1 choices of birthdays, since their birthday must match that of one of the first k 1 people.

Thus,

P(X = k) = 365 364 (365 k + 2) 365k1 k 1 365

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2021-12-05 00:00
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