No they have common factor of 3
No, 72 and 252 are not relatively prime. No pair of even numbers can be relatively prime.
they are not relatively prime
No, they are not relatively prime.
55 and 72 are relatively prime because they have no prime factors in common.
72 and 115 are relatively prime, having no common factors greater than 1.
No.
No.
72
Yes.
The factors of 39 are: 1, 3, 13, 39 The factors of 42 are: 1, 2, 3, 6, 7, 14, 21, 42 The factors of 72 are: 1, 2, 3, 4, 6, 8, 9, 12, 18, 24, 36, 72
The greatest common factor of 25 and 72 is 1, so they are relatively prime.
No, they have a common factor of 24.