document.write( "Question 1121053: In a group of students, 70 have a personal computers, 120 have a personal stereo and 41 have both. How many own at least one of these devices? Draw an appropriate Venn diagram. \n" ); document.write( "
Algebra.Com's Answer #736794 by Edwin McCravy(20055)\"\" \"About 
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In a group of students, 70 have a personal computers, 120 have a personal
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document.write( "There are two overlapping circles.  We pretend that the red circle contains\r\n" );
document.write( "all 70 students who have a personal computer. We pretend that the blue\r\n" );
document.write( "circle contains all 120 students who have a personal stereo.  The\r\n" );
document.write( "overlapping part is in both circles and we pretend that the overlapping\r\n" );
document.write( "part contains only the 41 students who have both a computer and a stereo. So\r\n" );
document.write( "we write 41 in the overlapping part:\r\n" );
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document.write( "The red circle contains all 70 students who have a personal computer.  and\r\n" );
document.write( "the 41 who have both are part of the 70, so that leaves 70-41 or 29 in the\r\n" );
document.write( "left part of the red circle, who only have a personal computer.  So we write\r\n" );
document.write( "29 in the left part of the red circle:\r\n" );
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document.write( "The blue circle contains all 120 students who have a personal stereo, and\r\n" );
document.write( "the 41 who have both are part of the 120, so that leaves 120-41 or 79 in the\r\n" );
document.write( "right part of the blue circle, who only have a personal stereo.  So we write\r\n" );
document.write( "79 in the right part of the blue circle:\r\n" );
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document.write( "Notice that there are 29 in the red circle that are not in the blue circle.\r\n" );
document.write( "So 29 students have a computer but no stereo. Notice that there are 79 in\r\n" );
document.write( "the blue circle that are not in the red circle.  So 79 students have a\r\n" );
document.write( "stereo but no computer.  And as we said earlier, the 41 in the middle that\r\n" );
document.write( "are in both circles are the 41 that have both a computer and a stereo.\r\n" );
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document.write( "So to determine how many students have one or the other (or both), that is,\r\n" );
document.write( "at least one, we add the three numbers together:\r\n" );
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document.write( " 29 students have a computer but no stereo\r\n" );
document.write( " 41 students have both a computer and a stereo\r\n" );
document.write( "+79 students have a stereo but no computer\r\n" );
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document.write( "149 students have at least one of the two devices\r\n" );
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document.write( "Edwin
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