document.write( "Question 1173263: A teacher has 20 boys and 10 girls in her class. In how many way can she select 6 of the children to be in a play if she must have 3 boys and 3 girls? \n" ); document.write( "
Algebra.Com's Answer #798470 by ikleyn(52781)\"\" \"About 
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document.write( "The teacher can choose 3 boys from 20 boys by  \"C%5B20%5D%5E3\" = \"%2820%2A19%2A18%29%2F%281%2A2%2A3%29\" = 1140 ways.\r\n" );
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document.write( "The teacher chooses 3 girls from 10 girls by  \"C%5B10%5D%5E3\" = \"%2810%2A9%2A8%29%2F%281%2A2%2A3%29\" = 120 ways.\r\n" );
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document.write( "Since the selections in each category are independent, the entire choice can be done in  1140*120 ways =  136800 ways.    ANSWER\r\n" );
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\n" ); document.write( "\n" ); document.write( "This problem is on COMBINATIONS.\r
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\n" ); document.write( "\n" ); document.write( "So, you should know what the combinations are and how to calculate them.\r
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\n" ); document.write( "\n" ); document.write( "You can learn about it from these introductory lessons on combinations\r
\n" ); document.write( "\n" ); document.write( "On Combinations,  see 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
\n" ); document.write( "\n" ); document.write( "    - Fundamental counting principle problems \r
\n" ); document.write( "\n" ); document.write( "    - OVERVIEW of lessons on Permutations and 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( "If you will come to the forum with new problems on  PERMUTATIONS  and  COMBINATIONS,\r
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\n" ); document.write( "\n" ); document.write( "please report me whether you are familiar with basic conceptions and methods of calculations \r
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\n" ); document.write( "\n" ); document.write( "and whether you just have read that lessons I recommended you.\r
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\n" ); document.write( "\n" ); document.write( "Good luck  (!)   and   Happy learning  (!)\r
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