document.write( "Question 1154170: In how many ways could a club of 28 appoint a committee of four people \n" ); document.write( "
Algebra.Com's Answer #776551 by ikleyn(52780)\"\" \"About 
You can put this solution on YOUR website!
.
\n" ); document.write( "
\r\n" );
document.write( "\r\n" );
document.write( "The number of ways to choose 4 items from 28 items is equal to  \r\n" );
document.write( "\r\n" );
document.write( "\r\n" );
document.write( "    \"C%5B28%5D%5E4\" = \"28%21%2F%284%21%2A%2828-4%29%21%29\" = \"28%21%2F%284%21%2A24%21%29\" = \"%2828%2A27%2A26%2A25%29%2F%281%2A2%2A3%2A4%29\" = 20475.    ANSWER\r\n" );
document.write( "\r\n" );
document.write( "\r\n" );
document.write( "It is the number of combinations of 28 items taken 4 at a time.\r\n" );
document.write( "\r\n" );
document.write( "\r\n" );
document.write( "\r\n" );
document.write( "    Usually,  for a student who only start studying this subject,  it is difficult to understand the meaning of these words.\r\n" );
document.write( "\r\n" );
document.write( "\r\n" );
document.write( "    In simple terms,   \"C%5B28%5D%5E4\"   is the number of all different  4-element subsets of the given set of  28  elements.\r\n" );
document.write( "\r\n" );
document.write( "\r\n" );
document.write( "    Notice that the order of 4 people in the committee IS NOT IMPORTANT (does not matter) in this problem. \r\n" );
document.write( "
\r
\n" ); document.write( "\n" ); document.write( "Solved.\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "--------------------\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "This problem is on  COMBINATIONS,\r
\n" ); document.write( "\n" ); document.write( "and it is a typical and basic problem on combinations.\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "Usually,  such problems are very first to get familiar with the subject.\r
\n" ); document.write( "
\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( "    - OVERVIEW of lessons on Permutations and Combinations\r
\n" ); document.write( "\n" ); document.write( "in this site.\r
\n" ); document.write( "
\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
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "The referred lessons are the part of this online textbook under the topic  \"Combinatorics: Combinations and permutations\". \r
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "Save the link to this textbook together with its description\r
\n" ); document.write( "
\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
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "into your archive and use when it is needed.\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( " \n" ); document.write( "
\n" );