Answer:
A common factor is a whole number which is a factor of two or more numbers.
[tex]factors \: of \: 9 = 1 \times 3 \times 3[/tex]
[tex]factors \: of \: 15 = 1 \times 3 \times 5[/tex]
since both of the numbers have only 1 and 3 in common.
therefore ,
Option A is correct.
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Additional information
★ The highest common factor (HCF) is the greatest factor that will divide into two or more numbers.
★ The lowest common multiple (LCM) is the smallest multiple that is common to two or more numbers.
hope helpful :D
