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APMOPS 2014 Question 27

APMOPS · APMOPS 2014

Question 27

Appending a positive integer $N$ at the end of any positive integer to form a new number (for example, appending 21 at the end of 35 gives 3521), if this new number is always divisible by $N$, then $N$ is called a “magic number”. Find the total number of “magic numbers” less than 600.