SOLUTION: What is the sum of the non-prime numbers of 12?

Question 200291: What is the sum of the non-prime numbers of 12?
Answer by solver91311(24713) (Show Source): You can put this solution on YOUR website!

I have to presume you meant What is the sum of the non-prime factors of 12.

First, list and categorize all of the integers from 1 to 12 inclusive:

1, factor of 12 and not prime by definition

2, factor of 12 but prime

3, factor of 12 but prime

4, factor of 12 and not prime because divisible by 2

5, not a factor of 12

6, factor of 12 and not prime because divisible by 2 and 3

7, 8, 9, 10, and 11, not a factor of 12

12, a factor of 12 and not prime because divisible by 2 and 3

So the factors that fit the criteria are 1, 4, 6, and 12. Add 'em up.

John

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