Links and References:
http://betterexplained.com/articles/u… (Regarding the birthday paradox)
http://www.bbc.com/news/magazine-2783… (more on the birthday paradox)
https://en.wikipedia.org/wiki/Birthda… (More on the birthday paradox)
http://dictionary.cambridge.org/dicti… (Paradox definition)
https://en.wikipedia.org/wiki/Pigeonh… (Pigeonhole principle)