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APMOPS 2011 Question 28

APMOPS · APMOPS 2011

Question 28

$S_n$ is defined as the sum of the digits in the whole number $n$. For example, $S_3=3$ and $S_{29}=2+9=11$. Find $S_1+S_2+\cdots+S_{2010}+S_{2011}$.