Difference between revisions of "2019 CIME I Problems/Problem 11"

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=Solution 1=
 
=Solution 1=
We don't know yet.
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The positive integers which are not <math>multiplicative</math> are <math>1, 2, 3, 4, 5, 6, 8, 12, 24</math>. These sum to <math>\boxed{65}</math>.
  
 
==See also==
 
==See also==
 
{{CIME box|year=2019|n=I|num-b=10|num-a=12}}
 
{{CIME box|year=2019|n=I|num-b=10|num-a=12}}
 
{{MAC Notice}}
 
{{MAC Notice}}

Revision as of 17:00, 4 October 2020

We define a positive integer to be $multiplicative$ if it can be written as the sum of three distinct positive integers $x, y, z$ such that $y$ is a multiple of $x$ and $z$ is a multiple of $y$. Find the sum of all the positive integers which are not $multiplicative$.

Solution 1

The positive integers which are not $multiplicative$ are $1, 2, 3, 4, 5, 6, 8, 12, 24$. These sum to $\boxed{65}$.

See also

2019 CIME I (ProblemsAnswer KeyResources)
Preceded by
Problem 10
Followed by
Problem 12
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15
All CIME Problems and Solutions

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