document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=236899>Question 236899</A>: <I><SPAN STYLE=\"word-break: break-all;\"> Prove that there must be at least 2 students at a college with the same last four digits of a social security number\r<BR>\n" );
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document.write( "So far, I've tried reasoning that there are 10 possible digits, and i have to choose 4 of them, so it would be a combination/permutation of 10 choose 4. (i'm not sure which one it is though) and where do I go from there </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #174278 by </B><A HREF=/tutors/aboutme.mpl?userid=scott8148><B>scott8148(6628)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=scott8148><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=scott8148><BR>You can <A HREF=\"/cgi-bin/embed-solution.mpl?show=1&solution=174278\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> the four digits range from 0000 to 9999 ___ 10,000 possibilities\r<BR>\n" );
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document.write( "if there are more than 10,000 students at the school, then there has to be duplication </SPAN>\n" );
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