document.write( "Question 1159464: In how many ways can you select a set of 3 letters from JasmineOrtz
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Algebra.Com's Answer #782490 by Edwin McCravy(20060)\"\" \"About 
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In how many ways can you select a set of 3 letters from JasmineOrtz
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document.write( "There are no repeated letters, so all letters are distinguishable.  \r\n" );
document.write( "You can choose the first letter any of 11 ways.\r\n" );
document.write( "That leaves 10 ways to choose the 2nd letter. \r\n" );
document.write( "That leaves 9 ways to choose the 3rd letter. \r\n" );
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document.write( "That's 11∙10∙9 = 990 ways to choose 3 letters where order matters\r\n" );
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document.write( "For example, amt, atm, tam, tma, mat, mta are all counted among the 990 above,\r\n" );
document.write( "but all of them are the same if the order they are in doesn't matter.  So we\r\n" );
document.write( "need to divide the 990 by the number of ways each one can be arranged, which\r\n" );
document.write( "will remove the \"extras\" from the 990.\r\n" );
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document.write( "In the example amt, atm, tam, tma, mat, mta, \r\n" );
document.write( "there are 3 ways to choose the 1st letter.\r\n" );
document.write( "That leaves 2 ways to choose the 2nd letter.\r\n" );
document.write( "That leaves 1 ways to choose the 3rd letter.\r\n" );
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document.write( "That's 3∙2∙1 = 6 ways. So each selection is counted 6 times too many among the\r\n" );
document.write( "990, so we need to divide the 990 by 3∙2∙1 or 6:\r\n" );
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document.write( "It's the same for any group of 3 letters, so  the answer is:\r\n" );
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document.write( "11∙10∙9   990\r\n" );
document.write( "------- = --- = 165.\r\n" );
document.write( " 3∙2∙1     6\r\n" );
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document.write( "Edwin
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