document.write( "Question 94351: find the number of permutations of the first 8 letters of the alphabet for each situation. taking 3 letters at a time \n" ); document.write( "
Algebra.Com's Answer #68679 by jim_thompson5910(35256)\"\" \"About 
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\n" ); document.write( "\n" ); document.write( "Since order does matter (this is because the word \"cab\" is different than \"abc\"), we can use the permutation formula:\r
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\n" ); document.write( "\n" ); document.write( "\"n%21%2F%28n-r%29%21\" Start with the given formula\r
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\n" ); document.write( "\n" ); document.write( "\"8%21%2F%288-3%29%21\" Plug in \"n=8\" (this is number of letters given) and \"r=3\" (this is the number of letters we can use together at a time)\r
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\n" ); document.write( "\n" ); document.write( "\"8%21%2F5%21\" Subtract \"8-3\" to get 5\r
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\n" ); document.write( "\n" ); document.write( "Expand 8!
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\n" ); document.write( "\n" ); document.write( "Expand 5!
\n" ); document.write( "\"%288%2A7%2A6%2A5%2A4%2A3%2A2%2A1%29%2F%285%2A4%2A3%2A2%2A1%29\"\r
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\n" ); document.write( "\n" ); document.write( "\"%288%2A7%2A6%2Across%285%2A4%2A3%2A2%2A1%29%29%2F%28cross%285%2A4%2A3%2A2%2A1%29%29\" Cancel\r
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\n" ); document.write( "\n" ); document.write( "\"8%2A7%2A6\" Simplify\r
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\n" ); document.write( "\n" ); document.write( "\"336\" Now multiply 8*7*6 to get 336\r
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\n" ); document.write( "\n" ); document.write( "So 8 choose 3 (where order does matter) yields 336 unique combinations\r
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