Question

how to find out the common factor of 60 and 90

Answer 1

By HCF
Hope this will help you

Answer 2

The greatest common factor of 60 and 90 can be computed by using the least common multiple aka lcm of 60 and 90. This is the easiest approach:

gcf (60,90) = 60×90/lcm(60,90)

=5400 /180 = 30

Alternatively, the gcf of 60 and 90 can be found using the prime factorization of 60 and 90:

The prime factorization of 60 is: 2 x 2 x 3 x 5

The prime factorization of 90 is: 2 x 3 x 3 x 5

The prime factors and multiplicities 60 and 90 have in common are: 2 x 3 x 5

2 x 3 x 5 is the gcf of 60 and 90

gcf(60,90) = 30