document.write( "Question 1197700: From a survey involving 1,000 university students, a market research company found that 750 students owned laptops, 410 owned cars, and 370 owned cars and laptops. If a university student is selected at random, what is each (empirical) probability?
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Algebra.Com's Answer #831079 by ikleyn(52787) $\"\"$ $\"About$

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\n" ); document.write( "From a survey involving 1,000 university students, a market research company found
\n" ); document.write( "that 750 students owned laptops, 410 owned cars, and 370 owned cars and laptops.
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\n" ); document.write( "(A) The student owns either a car or a laptop
\n" ); document.write( "(B) The student owns neither a car nor a laptop
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document.write( "(A)  This question asks \"either a car or a laptop, but not both\".\r\n" );
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document.write( "     We compute this amount as \r\n" );
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document.write( "          (n(car) + n(laptop) - n(both)) - n(both) = (750+410-370) - 370 = 420.\r\n" );
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document.write( "     Thus the probability is  P(question A) =  =  =  = 0.42 = 42%.      ANSWER\r\n" );
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document.write( "(B)  This question asks about the complementary probability to having a car OR a laptop.\r\n" );
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document.write( "     The number of students who own a car or a laptop is\r\n" );
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document.write( "         n(car) + n(laptop) - n(both) = 750 + 410 - 370 = 790.\r\n" );
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document.write( "      Thus the probability is  P(question B) =  =  = 0.21 = 21%.      ANSWER\r\n" );
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\n" ); document.write( "\n" ); document.write( "In this problem, the key subject to learn is the difference in calculating \" either - or \" from calculating single \" or \".\r
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\n" ); document.write( "\n" ); document.write( "                        To memorize :\r
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\n" ); document.write( "\n" ); document.write( "        The single \" or \" is \" or inclusive \".\r
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\n" ); document.write( "\n" ); document.write( "        The \" either-or \" is \" or exclusive \".\r
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