Question

What if most common factor of 42 and 15

Answer 1

The prime factorization of 15 is: 3 x 5The prime factorization of 42 is: 2 x 3 x 7The prime factors and multiplicities 15 and 42 have in common are: 33 is the gcf of 15 and 42gcf(15,42) = 3

Answer 2

I think it's 3.
1, 2, 3, 6, 7, 14, 21, 42
1,3,5,15
3 is the common factor