document.write( "Question 1122854: Lili has 20 friends. Among them are Kevin and Gerry, who are husband and wife.
\n" ); document.write( "Lili wants to invite six of her friends to her birthday party. If neither Kevin nor
\n" ); document.write( "Gerry will go to a party without the other, how many choices does Lili have?
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Algebra.Com's Answer #739046 by ikleyn(52814)\"\" \"About 
You can put this solution on YOUR website!
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\n" ); document.write( "\n" ); document.write( "If each separate \"choice\" is the group of 6 invited friends, then the solution is THIS :\r
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document.write( "    the number of choices Lili has = \"C%5B18%5D%5E6\" + \"C%5B18%5D%5E4\"\r\n" );
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document.write( "    where first addend in the formula represents  \"6 of 18 including NEITHER Kevin NOR Gerry\", \r\n" );
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document.write( "    while the second addend in the formula represents \"4 of 18 assuming that both Kevin and Gerry are included\".\r\n" );
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\n" ); document.write( "\n" ); document.write( "I assume that you are familiar with Combinations to that extent to calculate the numbers from the formula on your own.\r
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\n" ); document.write( "\n" ); document.write( "If not - then you have a good chance and a happy opportunity to learn about Combinations from introductory lessons \r
\n" ); document.write( "\n" ); document.write( "    - Introduction to Combinations\r
\n" ); document.write( "\n" ); document.write( "    - PROOF of the formula on the number of Combinations\r
\n" ); document.write( "\n" ); document.write( "    - Problems on Combinations\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 lessons are the part of this online textbook under the topic  \"Combinatorics: Combinations and permutations\". \r
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\n" ); document.write( "\n" ); document.write( "Save the link to this textbook together with its description\r
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\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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