Answer:
A) 9 and 15.
Step-by-step explanation:
First, let's see what each number's factor is:
A)
9 : 1, 3 & 9
15 : 1, 3, 5 & 15
B)
6 : 1, 2, 3 & 6
10 : 1, 2, 5 & 10
C)
8 : 1, 2, 4 & 8
12 : 1, 2, 3, 4, 6 & 12
Therefore, The number 3 is a common factor of A) 9 and 15.
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