document.write( "Question 1025521: Please help me this problem is driving me crazy. I need to know what equation do I use. \r
\n" ); document.write( "\n" ); document.write( "A computer password is required to be 5 characters long. How many passwords are possible if the password requires 3 letter(s) and 2 digits (numbers 0-9), where no repetition of any letter or digit is allowed? \r
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Algebra.Com's Answer #640838 by Edwin McCravy(20055)\"\" \"About 
You can put this solution on YOUR website!
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document.write( "Choose the places in the password for the 2 digits to occur\r\n" );
document.write( "in 5C2 = 10 ways.  They are\r\n" );
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document.write( "DDLLL, DLDLL, DLLDL, DLLLD, LDDLL, \r\n" );
document.write( "LDLDL, LDLLD, LLDDL, LLDLD, LLLDD.\r\n" );
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document.write( "where D stands for a digit and L stands for a letter.\r\n" );
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document.write( "For each of these 10 ways, there are 10 ways to choose the\r\n" );
document.write( "first digit in the password.  That's 10*10 = 100\r\n" );
document.write( "ways to pick the form and the first digit in the\r\n" );
document.write( "password.\r\n" );
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document.write( "For each of these 100 ways, there are 9 ways left to choose \r\n" );
document.write( "the second digit in the password.  That's 100*9 = 900 ways \r\n" );
document.write( "to pick the form and the first and second digits in the \r\n" );
document.write( "password.\r\n" );
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document.write( "For each of these 900 ways, there are 26 ways to choose the\r\n" );
document.write( "letter that comes first in the password.  That's 900*26 = \r\n" );
document.write( "23400 ways to pick the form, the two digits and the first\r\n" );
document.write( "letters in the password.\r\n" );
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document.write( "For each of these 23400 ways, there are 25 ways left to choose \r\n" );
document.write( "the second letter in the password.  That's 23400*25 = 585000 \r\n" );
document.write( "ways to pick the form, the two digits and the first two\r\n" );
document.write( "letters in the password.\r\n" );
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document.write( "For each of these 585000 ways, there are 24 ways left to choose \r\n" );
document.write( "the third letter in the password.  That's 585000*24 = 14040000 \r\n" );
document.write( "ways to pick the form, the two digits and the 3 letters in the \r\n" );
document.write( "password.\r\n" );
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document.write( "Answer 14040000.\r\n" );
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document.write( "Edwin
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