Is 16 and 40 relatively prime?

No

Step-by-step explanation:

Relatively prime means that the only common factor the 2 numbers share is 1

factors of 16 are 1, 2, 4, 8, 16

factors of 40 are 1, 2, 4, 5, 8, 10, 20, 40

common factors are 1, 2, 4, 8

Hence 16 and 40 are not relatively prime