document.write( "Question 572550: How mnay people do you need to gather to be sure that at least two of them have a birthday in the same month? \n" ); document.write( "
Algebra.Com's Answer #368592 by richard1234(7193)\"\" \"About 
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There are 12 months, so according to pigeonhole principle, you need 13 so that at least two of them have a birthday in the same month. \n" ); document.write( "
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