Yes GCF can be 1 because if it doesn't have any other common factors than it's one
The GCF is 1.
The GCF is 1.
The GCF is 1.
The GCF is 1.
The GCF of 4 and 10 is 2.
The GCF is 1.
The GCF is 1.
The GCF is 1.
GCF(1, 5, 10) = 1. The GCF of any set of numbers containing 1 must be 1.
The GCF is: 1
The GCF is 1.
The GCF is 1.
The GCF is 1.