document.write( "Question 1210205: How many 7-digit sequences have a digit that appears at least 6 times?\r
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\n" ); document.write( "\n" ); document.write( "(For example, 3339333 and 0200000 are two such sequences. A sequence is allowed to begin with 0.)
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Algebra.Com's Answer #851610 by Edwin McCravy(20056)\"\" \"About 
You can put this solution on YOUR website!
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document.write( "Case 1: ALL the digits are the same\r\n" );
document.write( "There are 10 ways all 7 digits can be the same.\r\n" );
document.write( "That's 10 ways for Case 1.\r\n" );
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document.write( "Case 2:\r\n" );
document.write( "6 of the digits are the same and 1 is different.\r\n" );
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document.write( "We can choose the digit that occurs 6 times, 10 ways.\r\n" );
document.write( "We can choose the digit that occur only once, 9 ways.\r\n" );
document.write( "We can choose the position for the digit that occurs only once, 7 ways.\r\n" );
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document.write( "That's (10)(9)(7) = 630 ways for Case 2.\r\n" );
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document.write( "Answer: 10 + 630 = 640 ways.\r\n" );
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document.write( "Edwin
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