There are 30 days in June. 5 students have their birthdays in June. Birthdays are independent of each other and all dates equally likely. What is the probability that at least 2 students have the same birthday?

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Answer 1 · 2018-05-30T07:30:45

#0.29627#

#P = 1 - P("all students have different birthday")#
#= 1 - (30/30)(29/30)(28/30)(27/30)(26/30)#
#= 1 - ((30!)/(25!))/30^5#
#= 0.29627#