document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=1205866>Question 1205866</A>: <I><SPAN STYLE=\"word-break: break-all;\"> A survey of a group's web habits for the past month obtained the following information.\r<BR>\n" );
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document.write( "30% visited Facebook.<BR>\n" );
document.write( "38% visited LinkedIn.<BR>\n" );
document.write( "36% visited Google.<BR>\n" );
document.write( "16% visited Facebook and LinkedIn.<BR>\n" );
document.write( "16% visited Facebook and Google.<BR>\n" );
document.write( "18% visited LinkedIn and Google.<BR>\n" );
document.write( "9% visited all three sites.\r<BR>\n" );
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document.write( "Find the percentage that visited none of these three sites last month.\r<BR>\n" );
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document.write( "Hint: Draw a Venn diagram for three sets. Then label appropriate parts from the given information. </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #842933 by </B><A HREF=/tutors/aboutme.mpl?userid=ikleyn><B>ikleyn(52777)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=ikleyn><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=ikleyn><BR>You can <A HREF=\"/cgi-bin/embed-solution.mpl?show=1&solution=842933\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> .<BR>\n" );
document.write( "<PRE STYLE=\"white-space: pre-wrap; white-space: -moz-pre-wrap; white-space: -pre-wrap; white-space: -o-pre-wrap; word-wrap: break-word;\">\r\n" );
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document.write( "Find the percentage of those who visited at least on of the three sites.\r\n" );
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document.write( "Use the Inclusion-Exclusion principle/formula\r\n" );
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document.write( "    30% + 38% + 36% - 15% - 16% - 18% + 9% = 64%.\r\n" );
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document.write( "The percentage of those who visited none of these three sites last month \r\n" );
document.write( "is the complement of 64% to 100%, i.e.  100% - 64% = 36%.\r\n" );
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document.write( "<U>ANSWER</U>.  36%.\r\n" );
document.write( "</PRE>\r<BR>\n" );
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document.write( "Solved.\r<BR>\n" );
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document.write( "------------------\r<BR>\n" );
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document.write( "On inclusion-exclusion principle, &nbsp;see this Wikipedia article\r<BR>\n" );
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document.write( "https://en.wikipedia.org/wiki/Inclusion%E2%80%93exclusion_principle\r<BR>\n" );
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document.write( "To see many other similar &nbsp;(and different) &nbsp;solved problems, &nbsp;see the lessons\r<BR>\n" );
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document.write( "&nbsp;&nbsp;&nbsp;&nbsp;- <A  rel=nofollow HREF=http://www.algebra.com/algebra/homework/word/misc/Counting-elements-in-sub-sets-of-a-given-finite-set.lesson>Counting elements in sub-sets of a given finite set</A>\r<BR>\n" );
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document.write( "&nbsp;&nbsp;&nbsp;&nbsp;- <A  rel=nofollow HREF=https://www.algebra.com/algebra/homework/word/misc/Advanced-probs-counting-elements-in-sub-sets-of-a-given-finite-set.lesson>Advanced problems on counting elements in sub-sets of a given finite set</A>\r<BR>\n" );
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document.write( "&nbsp;&nbsp;&nbsp;&nbsp;- <A  rel=nofollow HREF=https://www.algebra.com/algebra/homework/word/misc/Challenging-problems-on-counting-elements-in-subsets-of-a-given-finite-set.lesson>Challenging problems on counting elements in subsets of a given finite set</A> \r<BR>\n" );
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document.write( "&nbsp;&nbsp;&nbsp;&nbsp;- <A  rel=nofollow HREF=https://www.algebra.com/algebra/homework/word/misc/Selected-problems-on-counting-elements-in-subsets-of-a-given-finite-set.lesson>Selected problems on counting elements in subsets of a given finite set</A> \r<BR>\n" );
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document.write( "&nbsp;&nbsp;&nbsp;&nbsp;- <A  rel=nofollow HREF=https://www.algebra.com/algebra/homework/Permutations/Inclusion-Exclusion-principle.lesson>Inclusion-Exclusion principle problems</A> \r<BR>\n" );
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document.write( "in this site.\r<BR>\n" );
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document.write( "Happy learning (!)\r<BR>\n" );
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document.write( " </SPAN>\n" );
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