Question

Select ALL choices where 3 is the GCF of the pair of n umbers,

A:9, 15
B:9,21
C:12, 18
D:15, 27
E:30. 45
Please respond

Answer 1

A, B, D

Explanation:

A: factors of 9= 1, 3, 9/factors of 15= 1, 3, 5, 15. Their largest common one is 3

B: factors of 9= 1, 3, 9/factors of 21= 1, 3, 7, 21. Their largest common factor is 3

C: factors of 12= 1, 2, 3, 4, 6, 12/ factors of 18= 1, 2, 3, 6, 9, 18. Their largest common factor is 6, not 3

D: factors of 15= 1, 3, 5, 15/ factors of 27= 1, 3, 9, 27. Their biggest common factor is 3.

E: factors of 30= 1, 2, 3, 5, 10, 15, 30/ factors of 45= 1, 3, 5, 9, 15, 45. Their largest common factor is 15, not 3.