document.write( "Question 1009281: In a certain town, 75% of households own a cell phone, 45% own a laptop and 40% ownboth. A) draw a venn diagram for this problem.
\n" ); document.write( " B) determine the probability that a randomly selected person owns a laptop or a cell phone. ( Please show all work ) \n" ); document.write( "
Algebra.Com's Answer #626998 by Edwin McCravy(20059)\"\" \"About 
You can put this solution on YOUR website!
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document.write( "The whole red circle C contains the percentage of all people\r\n" );
document.write( "who own a cell phone.\r\n" );
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document.write( "The whole blue circle L contains the percentage of all people who\r\n" );
document.write( "own a laptop.\r\n" );
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document.write( "The red circle consists of the regions indicated by a and b.\r\n" );
document.write( "The blue circle consists of the regions indicated by b and c.\r\n" );
document.write( "The region indicated by b represent the percentage of people\r\n" );
document.write( "who own both a cell phone and a laptop.\r\n" );
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document.write( "We look at the most inclusive clue first:\r\n" );
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\n" ); document.write( "40% own both.
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document.write( "Those who own both are represented by the region marked b, the\r\n" );
document.write( "region where both circles overlap.  So we put 40% in that middle\r\n" );
document.write( "region where the circles overlap:\r\n" );
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document.write( "Next we look at this clue:\r\n" );
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\n" ); document.write( "75% of households own a cell phone
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document.write( "This is the entire red circle C.  It already contains 40% in\r\n" );
document.write( "the part that overlaps the blue circle.  So to determine what \r\n" );
document.write( "percentage goes in region a, we subtract 75%-40% and get 35%\r\n" );
document.write( "to go in the region a:\r\n" );
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document.write( "Next we look at this clue:\r\n" );
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\n" ); document.write( "45% own a laptop
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document.write( "This is the entire blue circle L.  It already contains 40% in\r\n" );
document.write( "the part that overlaps the red circle.  So to determine what \r\n" );
document.write( "percentage goes in region c, we subtract 45%-40% and get 5%\r\n" );
document.write( "to go in the region c:\r\n" );
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document.write( "So far we have that:\r\n" );
document.write( "30% own a cell phone but do not own a laptop.\r\n" );
document.write( "40% own both a cell phone and a laptop.\r\n" );
document.write( "5% own a laptop but do not own a cell phone.\r\n" );
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document.write( "But some people do not own either.  They are in the region\r\n" );
document.write( "inside the big rectangle but outside of both circles, indicated\r\n" );
document.write( "by the letter d.\r\n" );
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document.write( "To find out what percent goes in this outer region d, we add what the\r\n" );
document.write( "percents in the three regions we have already filled in:\r\n" );
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document.write( "30% + 40% + 5 % = 75%\r\n" );
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document.write( "and subtract from 100%\r\n" );
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document.write( "100% - 75% = 25%.\r\n" );
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document.write( "So we put 25% in the outside region marked d:\r\n" );
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\n" ); document.write( "B) determine the probability that a randomly selected person owns
\n" ); document.write( " a laptop or a cell phone.
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document.write( "We just add the three percentages inside the circles (which we\r\n" );
document.write( "already did above to calculate the 25%).\r\n" );
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document.write( "30% + 40% + 5 % = 75%\r\n" );
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document.write( "Edwin

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