document.write( "Question 1160018: If three people roll a dice once, how many ways can the sum of the three people’s rolls add up to exactly 9? \n" ); document.write( "
Algebra.Com's Answer #783172 by ikleyn(52781)\"\" \"About 
You can put this solution on YOUR website!
.
\n" ); document.write( "
\r\n" );
document.write( "\r\n" );
document.write( "In other form, the question is\r\n" );
document.write( "\r\n" );
document.write( "\r\n" );
document.write( "    How many solutions does this equation have\r\n" );
document.write( "\r\n" );
document.write( "        \"x%5B1%5D\" + \"x%5B2%5D\" + \"x%5B3%5D\" = 9\r\n" );
document.write( "\r\n" );
document.write( "    in positive integer numbers \"x%5B1%5D\", \"x%5B2%5D\" and \"x%5B3%5D\" ?\r\n" );
document.write( "\r\n" );
document.write( "\r\n" );
document.write( "The solution can be done using the \"Stars and Bars method\", which gives in this case the answer  \r\n" );
document.write( "\r\n" );
document.write( "         \"C%5B9-1%5D%5E%283-1%29\" = \"C%5B8%5D%5E2\" = \"%288%2A7%29%2F2\" = 4*7 = 28.\r\n" );
document.write( "\r\n" );
document.write( "\r\n" );
document.write( "ANSWER.  28 different solutions   //  (accounting for all possible permutations, cases and sub-cases . . . )\r\n" );
document.write( "
\r
\n" ); document.write( "\n" ); document.write( "Solved and answered.\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "-----------------\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "For the \"Stars and Bars method\", see the lesson\r
\n" ); document.write( "\n" ); document.write( "    - Stars and bars method for Combinatorics problems \r
\n" ); document.write( "\n" ); document.write( "in this site, \r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "or, alternatively, this Wikipedia article\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "https://en.wikipedia.org/wiki/Stars_and_bars_%28combinatorics%29\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "https://en.wikipedia.org/wiki/Stars_and_bars_%28combinatorics%29\r
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "
\n" ); document.write( "
\n" );