Timeline for Group of $r$ people at least three people have the same birthday?

11 events

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Apr 13, 2017 at 12:20	history	edited	CommunityBot		replaced http://math.stackexchange.com/ with https://math.stackexchange.com/
Dec 13, 2015 at 20:31	comment	added	Markus Scheuer		@Pieter21: It would be nice, if you could elaborate your hint about the inclusion-exclusion principle in some detail. Your approach could provide some additional insight.
Dec 13, 2015 at 12:27	history	edited	Pieter21	CC BY-SA 3.0	added 224 characters in body
Dec 13, 2015 at 11:39	comment	added	Mithlesh Upadhyay		There is typo in option $(3)$ which should be $\displaystyle 1-( \frac{365\cdot364 \cdots(365-r+1)}{365^r} +{r\choose 2}\cdot \frac{365\cdot364\cdot363 \cdots (364-(r-2) +1)}{364^{r-2}})$, it seems correct. AFAIK : at least three means exactly three or more than three persons have birthday on same day.
Dec 13, 2015 at 11:26	comment	added	Pieter21		Should it be one of the 4 answers you gave?
Dec 13, 2015 at 11:20	comment	added	Pieter21		Expanded part 2. Part 3. did not need to expand, because it is just the rest of the universe.
Dec 13, 2015 at 11:20	history	edited	Pieter21	CC BY-SA 3.0	added 528 characters in body
Dec 13, 2015 at 11:11	comment	added	Mithlesh Upadhyay		How you are using inclusion-exclusion here? Part 2 and 3 need to expand.
Dec 13, 2015 at 11:04	comment	added	Pieter21		Can you tell which part of the answer is not clear? (While I'll expand on the answer a bit.)
Dec 13, 2015 at 8:01	comment	added	Mithlesh Upadhyay		Can you explain ?
Nov 24, 2015 at 16:00	history	answered	Pieter21	CC BY-SA 3.0