no...5 is but not 15
Yes, 4 and 15 are relatively prime.
Yes, they are relatively prime.
Yes, they are relatively prime.
Yes, they are relatively prime.
15 is not a prime number, so it can't be a prime factor.
No.
No!
No.
15 is relatively prime.
Yes, 15 and 21 are relatively prime because they have no common positive factors other than 1. The prime factorization of 15 is 3 and 5, while the prime factorization of 21 is 3 and 7. The only common factor is 3, which means they are not relatively prime.
Yes, they are.
No.