Difference between revisions of "Mock AIME 5 2005-2006 Problems/Problem 13"

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== Problem ==
 
== Problem ==
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Let <math>S</math> be the set of positive integers with only odd digits satisfying the following condition: any <math>x \in S</math> with <math>n</math> digits must be divisible by <math>5^n</math>. Let <math>A</math> be the sum of the <math>20</math> smallest elements of <math>S</math>. Find the remainder upon dividing <math>A</math> by <math>1000</math>.
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== Solution ==
  
 
== Solution ==
 
== Solution ==

Latest revision as of 20:20, 8 October 2014

Problem

Let $S$ be the set of positive integers with only odd digits satisfying the following condition: any $x \in S$ with $n$ digits must be divisible by $5^n$. Let $A$ be the sum of the $20$ smallest elements of $S$. Find the remainder upon dividing $A$ by $1000$.

Solution

Solution

See also

Mock AIME 5 2005-2006 (Problems, Source)
Preceded by
Problem 12
Followed by
Problem 14
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