No, that's not true.
8 and 16
25 and 36
8 and 16
15 and 16
8 and 16
8 and 16
24, 25 and 26
the greatest common factor of 19 and 13 is one because 19 or neither 13 are composite
The greatest common factor of a prime and a composite number is 1 if the composite number is not divisible by the prime number. 37 is a prime number and 50 is a composite number. Also, 50 is not divisible by 37 therefore GCF = 1.
Composite. All whole numbers ending in zero are composite.
No.
No.