document.write( "Question 1191918: . If the number of combinations of n objects taken 3 at a time is 20, how many permutations are there?
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Algebra.Com's Answer #823763 by ikleyn(52781) $\"\"$ $\"About$

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document.write( " = 20  means   = 20,\r\n" );
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document.write( "which implies  n*(n-1)*(n-2) = 120.\r\n" );
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document.write( "It means n = 6  (easy trial and error or easy reasoning);  \r\n" );
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document.write( "hence n! = 6! = 720.\r\n" );
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document.write( "ANSWER.  720 permutations.\r\n" );
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