document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=1155837>Question 1155837</A>: <I><SPAN STYLE=\"word-break: break-all;\"> Out of 100 persons surveyed ,75% had a personal computer ,68% had a dishwasher, 85% had a refrigerator and 80% had a video recorder. How many people had all four items?  </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #778535 by </B><A HREF=/tutors/aboutme.mpl?userid=ikleyn><B>ikleyn(52832)</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=778535\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> .\r<BR>\n" );
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document.write( "There is no enough data to answer the question.\r<BR>\n" );
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document.write( "Hello, I got your message (as a comment).\r<BR>\n" );
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document.write( "Let me repeat it again: the problem formulation does not bring enough information to be solved.\r<BR>\n" );
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document.write( "I found and saw precisely this formulation in other sites in the Internet: I made my own search and research.\r<BR>\n" );
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document.write( "Again: all these posts are DEFECTIVE.\r<BR>\n" );
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document.write( "Your \"solution\", which you presented in your comment, is INCORRECT (both solutions).\r<BR>\n" );
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document.write( "To disprove it, let consider more simple problem.\r<BR>\n" );
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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" );
document.write( "    Out of 100 people surveyed, 75 had a PC and 68 had a dishwasher.\r\n" );
document.write( "    How many people had all these items ?\r\n" );
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document.write( "Let assume that these 100 people are numbered from 1 to 100 and lined in a row.\r<BR>\n" );
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document.write( "Let's consider two cases.\r<BR>\n" );
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document.write( "    Case 1. These 68 are those with numbers from 1 to 68,\r\n" );
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document.write( "            and these 75 are those with numbers from 1 to 75.\r\n" );
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document.write( "            Then the number of those who has both items is 68.\r\n" );
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document.write( "    Case 2. These 68 are those with numbers from 1 to 68,\r\n" );
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document.write( "            but these 75 are those with numbers from 100 to 26.\r\n" );
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document.write( "            Then the number of those who has both items is from 26 to 68, i.e.  68-25 = 43.\r\n" );
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document.write( "Thus in these different cases we have two different answers.\r<BR>\n" );
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document.write( "It means that the problem does not allow to get a UNIQUE answer --- exactly as I stated.<BR>\n" );
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document.write( "Next.\r<BR>\n" );
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document.write( "This forum works THIS WAY:\r<BR>\n" );
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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" );
document.write( "    The visitor posts the problem.\r\n" );
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document.write( "    If the problem is posed correctly, in a right way, the tutor solves it.\r\n" );
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document.write( "    If the problem is posed INCORRECTLY (as in your case), the tutor NATURALLY does not solve it.\r\n" );
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document.write( "    In this case, the tutor may say to the visitor, that the problem has deficiencies (is DEFECTIVE), \r\n" );
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document.write( "     but the tutor is not obliged to explain, what the deficiencies are and so on. Such explanation IS NOT the tutor's duty.\r\n" );
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document.write( "    These are VERY NATURAL rules, and it is assumed, that the visitor is so smart and so much educated, that \r\n" );
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document.write( "    does understand it without repeating explanation.\r\n" );
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document.write( "    Otherwise, this forum would die after one week of work.\r\n" );
document.write( "</PRE>\r<BR>\n" );
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document.write( "These rules are presented somewhere in the special section of the forum,<BR>\n" );
document.write( "but they are so OBVIOUS that it would be strange to repeat them again and again.\r<BR>\n" );
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document.write( "In each regular day, I serve 10 - 15 - 20 posts/problems from visitors, and, NATURALLY, <BR>\n" );
document.write( "have no an opportunity to make so extended explanations.\r<BR>\n" );
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document.write( "Next.\r<BR>\n" );
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document.write( "To complete my post in positive mode, I will refer to the lessons in this site, which are close to your \"problem\".\r<BR>\n" );
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document.write( "These lessons are\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( "First of them is introductory lesson.\r<BR>\n" );
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document.write( "The other two are advanced.\r<BR>\n" );
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document.write( "After reading these lessons, you will understand the subject MUCH BETTER.\r<BR>\n" );
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document.write( "And PLEASE, post me some message, confirming that you saw and have read these lines.\r<BR>\n" );
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document.write( "If you will post your words to me, then PLEASE REFER to the problem's ID number 1155837.\r<BR>\n" );
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document.write( "Happy learning (!)\r<BR>\n" );
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