document.write( "Question 716619: in how many different ways can 4 persons be seated in a consecutive row of seven seats??\r
\n" ); document.write( "\n" ); document.write( "2. a shelf contain 5 red books, 4 blue books, and 3 green books. how many different orders can they be arranged if all books of the same color must kept together?
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Algebra.Com's Answer #439923 by Edwin McCravy(20060)\"\" \"About 
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in how many different ways can 4 persons be seated in a consecutive row of seven seats??
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document.write( "7 position 4 = P(7,4) = 7·6·5·4 = 840\r\n" );
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\n" ); document.write( "2. a shelf contain 5 red books, 4 blue books, and 3 green books. how many different orders can they be arranged if all books of the same color must kept together?
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document.write( "First, there are P(3,3) = 3! ways we can choose the order of colors,\r\n" );
document.write( "that is, (Red,Blue,Green), (Red,Green,Blue), (Blue, Red,Green),\r\n" );
document.write( "(Blue,Green,Red), (Green,Red,Blue), (Green,Blue,Red)\r\n" );
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document.write( "Then for each of those 3! ways, there are P(5,5) = 5! ways to arrange the 5\r\n" );
document.write( "red books, P(4,4) = 4! ways to arrange the blue books, and P(3,3) = 3! ways\r\n" );
document.write( "to arrange the green books.  \r\n" );
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document.write( "Answer 3!·5!·4!·3! = 6·120·24·6 = 103,680 ways.\r\n" );
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document.write( "Edwin
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