4. What is the greatest common factor of 12 and 20?
A. 8
B. 6
C. 4
D. 2
5. The greatest common factor of 20 and 30 is ____
A. 30 B. 20 C. 10 D. 5
6. Which is the prime factorization of 36? A.2 x 3 x 2 x 2
B. 2 x 2 x 3 x 3
C. 2 x 2 x 2 x 3 x3
D. 2 x 2 x 2 x 2 x 3 x 3
7. What is the greatest common factor of 9 and 21?
A. 3 B. 7 C. 9 D. 12
8. The greatest common factor of 14 and 28 is ____
A. 7 B. 12 C. 14 D. 28
9. What is the least common multiple of 8 and 3?
A. 24 B. 12 C. 6 D. 3
10. The LCM of 5 and 6 is _____.
A. 60 B. 30 C. 15 D. 5 ​