document.write( "Question 1066088: In a 10-item Mathematics problem-solving test, how many ways can you select 5 problems to solve? How many ways can you select the 5 questions if you are required to answer question number 10? \n" ); document.write( "
Algebra.Com's Answer #681467 by swincher4391(1107)\"\" \"About 
You can put this solution on YOUR website!
Part a)\r
\n" ); document.write( "\n" ); document.write( "Since it appears that the order does not matter (we are just choosing any 5 at once), then we are using a combination. A couple of different ways to compute this.\r
\n" ); document.write( "\n" ); document.write( "You can use the nCr button on your calculator, but I will do it using the formula.\r
\n" ); document.write( "\n" ); document.write( "So nCr = \"n%21%2F%28%28n-r%29%21%2A+r%21%29\"\r
\n" ); document.write( "\n" ); document.write( "We are finding 10 C 5 = \"+10%21+%2F%285%21+%2A+5%21%29+\"\r
\n" ); document.write( "\n" ); document.write( "10! is quite large, so let's try to do some simplification.\r
\n" ); document.write( "\n" ); document.write( "\r
\n" ); document.write( "\n" ); document.write( "\r
\n" ); document.write( "\n" ); document.write( "\"%2810%2A9%2A8%2A7%2A6%29%2F%285%2A4%2A3%2A2%2A1%29\"\r
\n" ); document.write( "\n" ); document.write( "\"%28cross%2810%29%2A9%2A8%2A7%2A6%29%2F%28cross%285%29%2A4%2A3%2Across%282%29%2A1%29\"\r
\n" ); document.write( "\n" ); document.write( "\"%289%2A8%2A7%2A6%29%2F%284%2A3%29\"\r
\n" ); document.write( "\n" ); document.write( "\"%28cross%289%293%2Across%288%292%2A7%2A6%29%2F%28cross%284%29%2Across%283%29%29\"\r
\n" ); document.write( "\n" ); document.write( "and 3 * 2* 7 * 6 is \"highlight%28252%29\".\r
\n" ); document.write( "\n" ); document.write( "----------------------------------------------
\n" ); document.write( "Part b)\r
\n" ); document.write( "\n" ); document.write( "10 is fixed so we really only have 9 questions and we are choosing 4.\r
\n" ); document.write( "\n" ); document.write( "So 9 C 4 = \r
\n" ); document.write( "\n" ); document.write( "\"%289%2A8%2A7%2A6%2A5%2A4%2A3%2A2%2A1%29%2F%28%285%2A4%2A3%2A2%2A1%29%284%2A3%2A2%2A1%29%29\"\r
\n" ); document.write( "\n" ); document.write( "\"%289%2A8%2A7%2A6%29%2F%284%2A3%2A2%2A1%29\"\r
\n" ); document.write( "\n" ); document.write( "\r
\n" ); document.write( "\n" ); document.write( "So 3 * 7 * 6 = \"highlight%28126%29\"\r
\n" ); document.write( "\n" ); document.write( "------------------------------------
\n" ); document.write( "Finally, Google will do it for you as well.\r
\n" ); document.write( "\n" ); document.write( "10 choose 5 : https://www.google.com/#q=10+choose+5\r
\n" ); document.write( "\n" ); document.write( "9 choose 4 : https://www.google.com/#q=9+choose+4
\n" ); document.write( "
\n" ); document.write( "
\n" );