document.write( "Question 1164107: Why is the following not a valid divisibility test for the
\n" ); document.write( "number 8? “A number is divisible by 8 if it is divisible by
\n" ); document.write( "both 4 and 2.” Support your answer with an appropriate
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Algebra.Com's Answer #788429 by Edwin McCravy(20060)\"\" \"About 
You can put this solution on YOUR website!
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document.write( "One reason is this counter-example:\r\n" );
document.write( "20 is not divisible by 8 yet it's divisible by by both 4 and 2.\r\n" );
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document.write( "Also, if a number is divisible by 4, it's automatically divisible by 2, so\r\n" );
document.write( "there would be no need to say that it's divisible by 2.\r\n" );
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document.write( "The sum of two multiples of 8 is also a multiple of 8. \r\n" );
document.write( "Since 1000 is divisible by 8, then any number that ends in 000 is a multiple\r\n" );
document.write( "of 1000 and is divisible by 8.  So if the number formed by the last three\r\n" );
document.write( "digits is a multiple of 8 then the number is divisible by 8, because it's\r\n" );
document.write( "the sum of two multiples of 8.\r\n" );
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document.write( "For example, 17216. The last three digits are 216 and it is divisible by 8.\r\n" );
document.write( "Thus, 17216 is divisible by 8.  (That's because it's 17000+216 and both 17000\r\n" );
document.write( "and 216 are divisible by 8.)  \r\n" );
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document.write( "Edwin
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