document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=1054859>Question 1054859</A>: <I><SPAN STYLE=\"word-break: break-all;\"> In a survey of 380 households regarding the ownership of VCRs and DVD players, the following data was obtained:<BR>\n" );
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document.write( "350 households own one or more VCRs.\r<BR>\n" );
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document.write( "&#8203;180 households own one or more VCRs and one or more DVD players.\r<BR>\n" );
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document.write( "&#8203;13 households do not own a VCR or a DVD player.\r<BR>\n" );
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document.write( "How many households only own one or more DVD players?\r<BR>\n" );
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document.write( "20 households<BR>\n" );
document.write( "29 households<BR>\n" );
document.write( "19 households<BR>\n" );
document.write( "16 households<BR>\n" );
document.write( "17 households<BR>\n" );
document.write( "30 households\r<BR>\n" );
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document.write( "Please explain. thank you<BR>\n" );
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document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #670061 by </B><A HREF=/tutors/aboutme.mpl?userid=Edwin+McCravy><B>Edwin McCravy(20060)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=Edwin+McCravy><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=Edwin+McCravy><BR>You can <A HREF=\"/cgi-bin/embed-solution.mpl?show=1&solution=670061\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=drawing%28300%2C200%2C-4%2C4%2C-2%2C4.8%2Crectangle%28-4%2C-1.6%2C4%2C4.4%29%2C+locate%28-2%2C1.8%2Ca%29%2Clocate%281.5%2C1.7%2Cc%29%2Clocate%28-3.7%2C-1%2Cd%29%2C+red%28locate%28-3.9%2C2.8%2CVCR%29%29%2C+locate%28-.1%2C1.8%2Cb%29%2Cred%28circle%28-sqrt%282%29%2Csqrt%282%29%2C2%29%29%2Cred%28circle%28-sqrt%282%29%2Csqrt%282%29%2C1.95%29%29%2Cred%28circle%28-sqrt%282%29%2Csqrt%282%29%2C1.975%29%29%2C%0D%0Ablue%28circle%28sqrt%282%29%2Csqrt%282%29%2C2%29%2Ccircle%28sqrt%282%29%2Csqrt%282%29%2C1.95%29%2Ccircle%28sqrt%282%29%2Csqrt%282%29%2C1.975%29%29%2C%0D%0Ablue%28locate%283.3%2C2.8%2CDVD%29%29%0D%0A+%29 ALIGN=MIDDLE   DISABLED_style= \"max-width:90%; height:auto;\" ><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;\"><b>\r\n" );
document.write( "The red circle represents the set of households with VCRs.\r\n" );
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document.write( "The blue circle represents the set of households with VCRs.\r\n" );
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document.write( "1. \"a\" is the number of households with VCRs only, the left\r\n" );
document.write( "part of the red circle.\r\n" );
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document.write( "2. The overlapping part of both circles represents the set of \r\n" );
document.write( "households with both VCRs and DVDs.\r\n" );
document.write( "\"b\" is the number of households with both VCRs and DVD's.\r\n" );
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document.write( "3. \"c\" is the number of households with DVDs only, the right\r\n" );
document.write( "part of the blue circle.\r\n" );
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document.write( "4. \"d\" represents the number of households which have neither\r\n" );
document.write( "a VCR nor a DVD.\r\n" );
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document.write( "The question is:\r\n" );
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document.write( "How many households only own one or more DVD players? <BR>\n" );
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document.write( "So we want to know what \"c\" equals.\r\n" );
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document.write( "In a survey of 380 households regarding the ownership of VCRs and DVD players, the following data was obtained:<BR>\n" );
document.write( "&#8203;<BR>\n" );
document.write( "350 households own one or more VCRs. <BR>\n" );
document.write( "&#8203;180 households own one or more VCRs and one or more DVD players. <BR>\n" );
document.write( "&#8203;13 households do not own a VCR or a DVD player. <BR>\n" );
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document.write( "Those three sentences translate into these equations\r\n" );
document.write( "respectively: \r\n" );
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document.write( "a+b+c+d = 380\r\n" );
document.write( "a+b     = 350\r\n" );
document.write( "      d =  13\r\n" );
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document.write( "Subtract the second equation from the first:\r\n" );
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document.write( "    c+d = 30\r\n" );
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document.write( "Substitute d = 13 into that:\r\n" );
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document.write( "   c+13 = 30\r\n" );
document.write( "      c = 17\r\n" );
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document.write( "{This problem is obviously from a very old book.\r\n" );
document.write( "One dated back when DVDs had just come on the\r\n" );
document.write( "market.  Nobody has VCRs anymore unless they're\r\n" );
document.write( "left over from way back then.  :)  ]\r\n" );
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document.write( "Edwin</PRE></b> </SPAN>\n" );
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