document.write( "Question 1106657: How many two-digit even numbers can you form using the digits 0, 1, 2, 3, 4, 5, 6, 7, 8, 9?
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Algebra.Com's Answer #721694 by Edwin McCravy(20060)\"\" \"About 
You can put this solution on YOUR website!
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document.write( "If we could have 0 come first, and we didn't care \r\n" );
document.write( "whether they were even or odd, there would be these 100:\r\n" );
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document.write( "00, 01, 02, 03, ..., 08, 09, 10, 11, ..., 98, 99\r\n" );
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document.write( "We take away these 10, which are really 1-digit numbers: \r\n" );
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document.write( "00, 01, 02, 03, ..., 08, 09\r\n" );
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document.write( "and that leaves these 90:\r\n" );
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document.write( "10, 11, ..., 98, 99\r\n" );
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document.write( "half of those 90 are even and the other half odd, and\r\n" );
document.write( "since half of 90 is 45, we have these 45\r\n" );
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document.write( "10, 12, ..., 96, 98\r\n" );
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document.write( "So 45 is the answer to (a)\r\n" );
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document.write( "Now if we take away these 4 with repetition:\r\n" );
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document.write( "22, 44, 66, 88\r\n" );
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document.write( "then we have only 41\r\n" );
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document.write( "So 41 is the answer to (b)\r\n" );
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document.write( "Edwin
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