document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=1103160>Question 1103160</A>: <I><SPAN STYLE=\"word-break: break-all;\"> How many people would you have to have in a group so that there is a probability of at least 0.9 that at least two of them will have the same birthday? </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #717858 by </B><A HREF=/tutors/aboutme.mpl?userid=Boreal><B>Boreal(15235)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=Boreal><IMG SRC=http://www.algebra.com/images/aboutme-small.gif BORDER=0 alt=\"About Me\" VALIGN=MIDDLE></A>&nbsp;<IMG SRC=http://www.algebra.com/cgi-bin/show-face.mpl?user=Boreal><BR>You can <A HREF=\"/cgi-bin/embed-solution.mpl?show=1&solution=717858\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> Can do this on a spreadsheet where<BR>\n" );
document.write( "p(2) not is (364/365)<BR>\n" );
document.write( "P(3) not is (364/365)(363/365)<BR>\n" );
document.write( "p(22) not (1/365)^21*(364*363*...*341)<BR>\n" );
document.write( "Here, when not is less than 10% the probability of yes will be greater than or equal to 90%.<BR>\n" );
document.write( "n=41<BR>\n" );
document.write( "On a calculator, can do 365*364*363*... to about 345, then divide by 365^21.  That will keep it from overloading.  Then repeat, and when 326 changes to 325, it will be <10% or >=90%.\r<BR>\n" );
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