document.write( "Question 984075: Find a formula of the number of permutations of the set {1,2,3,,,,n} where exactly k numbers are in their natural position if you could help me please
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Algebra.Com's Answer #604887 by Edwin McCravy(20055)\"\" \"About 
You can put this solution on YOUR website!
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document.write( "We can choose the k numbers to be in their natural positions nCk ways.\r\n" );
document.write( "The other n-k numbers are not in their natural positions in !(n-k) ways.\r\n" );
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document.write( "Answer (nCk)*!(n-k)\r\n" );
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document.write( "Where !(n-k) = greatest integer not exceeding (n-k)!/e  where e = 2.718281828...\r\n" );
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document.write( "Edwin
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