0
Anonymous
The GCF is 1.
Wiki User
The GCF is 3.
16 and 21
16: 1 2 4 8 16 21: 1 3 7 21 gcf: 1
The GCF is 4.
The GCF of 12, 16 is 4.
The GCF of 16 and 30 is 2.
GCF of 21 and 42: 21GCF of 16 and 25: 1