document.write( "Question 827728: how many ways can 10 people sit in their seats if say person 3 can't sit between person 1 and 2 \n" ); document.write( "

Algebra.Com's Answer #498839 by Edwin McCravy(20055) $\"\"$ $\"About$

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document.write( "Explanation:\r\n" );
document.write( "We consider the \"trio\" (persons 1,3,2 in that order) as 1 single \"thing\" and\r\n" );
document.write( "that there are 8 \"things\", 7 single people and 1 \"trio\".  That's 8! ways.\r\n" );
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document.write( "Explanation:\r\n" );
document.write( "Just like the preceding case, we consider the \"trio\" (persons 2,3,1 in that\r\n" );
document.write( "order) as 1 single \"thing\" and that there are 8 \"things\", 7 single people and\r\n" );
document.write( "1 \"trio\".  That's also 8! or 40320 ways.\r\n" );
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document.write( "Answer:  10! - 2×8! = 3628800 - 2×40320 = 3548160 ways.\r\n" );
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document.write( "Edwin

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