document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=10787>Question 10787</A>: <I><SPAN STYLE=\"word-break: break-all;\"> Kathy had a party.  Everyone at the party shook hands with everyone else.<BR>\n" );
document.write( "How many people were at the party if there 78 handshakes? </SPAN>\n" );
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document.write( "IF there were only 2 people,then only 1 handshake wld have occured\r<BR>\n" );
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document.write( "If 3 ppl, then 3 hand shakes\r<BR>\n" );
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document.write( "If 4 people then 6\r<BR>\n" );
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document.write( "If n people  then its nC2 or n(n-1)/2 \r<BR>\n" );
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document.write( "So if 78 handshakes = n(n-1)/2 = 78\r<BR>\n" );
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document.write( "n(n-1) = 78x2<BR>\n" );
document.write( "       = 39 x2 x2<BR>\n" );
document.write( "       = 13x3x2x2<BR>\n" );
document.write( "      = 13x12<BR>\n" );
document.write( "So 12people were at the party </SPAN>\n" );
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