Math Logic and Vocabulary AK

1. 6

2. 7

3. 54

4. 11

5. 3

6. 1

7. 5 $$\eqalign{12\div3=4\\4+4+4=12\\3+4+5=12}$$

8. 5 $$\eqalign{35\div5=7\\7+7+7+7+7=35\\5+6+7+8+9=35}$$ 

9. 12 $$\eqalign{30\div3=10\\10+10+10=30\\8+10+12=30}$$

10. 5 $$\eqalign{21\div3=7\\7+7+7=21\\5+7+9=21}$$

11. A

2 is a factor, not a multiple.

12. B

1, 6 and 12 are factors of 60, but are not prime.