document.write( "Question 1130394: Jane, a quality-control inspector has thirteen assembly lines from which to choose products for testing. Each morning, she randomly selects one of the lines to work on for the day. Find the probability that no line is chosen more than once for inspection in a span of three days. \n" ); document.write( "

Algebra.Com's Answer #747083 by ikleyn(52787) $\"\"$ $\"About$

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document.write( "Imagine that all and each line are marked by the first 13 letters of English alphabet:\r\n" );
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document.write( "1  2  3  4  5  6  7  8  9  10  11  12  13\r\n" );
document.write( "A  B  C  D  E  F  G  H  I   J   K   L   M \r\n" );
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document.write( "Then the space of all possible events is the set of all 3-letter words comprising of these letters.\r\n" );
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document.write( "Repetitions of letters in these words are allowed.\r\n" );
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document.write( "It is easy to calculate the number of all such 3-letter words.\r\n" );
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document.write( "Any of 13 letter can stay in the 1-st position. This gives 13 opportunities.\r\n" );
document.write( "Any of 13 letter can stay in the 2-nd position. This gives 13 opportunities.\r\n" );
document.write( "Any of 13 letter can stay in the 3-rd position. This gives 13 opportunities.\r\n" );
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document.write( "In all, there are  such words.\r\n" );
document.write( "Correspondingly, there are  elements in the space of events, in all.\r\n" );
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document.write( "Now, the favorable events are those 3-letter words what have no repetitions.\r\n" );
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document.write( "The number of such words is exactly  13*12*11 = 1716.\r\n" );
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document.write( "Therefore, the probability under the question is equal to  \r\n" );
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document.write( " = 0.7811 = 78.11% (approximately).     ANSWER\r\n" );
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\n" ); document.write( "\n" ); document.write( "Very similar to the problem 4 of the lesson\r
\n" ); document.write( "\n" ); document.write( " - Selected probability problems from the archive \r
\n" ); document.write( "\n" ); document.write( "in this site.\r
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\n" ); document.write( "\n" ); document.write( "Also, you have this free of charge online textbook in ALGEBRA-II in this site\r
\n" ); document.write( "\n" ); document.write( " - ALGEBRA-II - YOUR ONLINE TEXTBOOK.\r
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\n" ); document.write( "\n" ); document.write( "The referred lesson is the part of this online textbook under the topic \"Solved problems on Probability\". \r
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\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "Save the link to this textbook together with its description\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "Free of charge online textbook in ALGEBRA-II
\n" ); document.write( "https://www.algebra.com/algebra/homework/complex/ALGEBRA-II-YOUR-ONLINE-TEXTBOOK.lesson\r
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\n" ); document.write( "\n" ); document.write( "into your archive and use when it is needed.\r
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