Answer :
If you list out the factors of each number, it would look something like this:
36: 1,2,3,4,6,9,12,18,36
40: 1,2,4,5,8,10,20,40
In this case, the GCF of both numbers would be 4
36: 1,2,3,4,6,9,12,18,36
40: 1,2,4,5,8,10,20,40
In this case, the GCF of both numbers would be 4
