What is the greatest common factor of 20 and 36? 2 4 5 6

It's 4

4*5=20

4*9=36

The other numbers don't work

For this case we have that, by definition, the greatest common factor or GCF of two numbers is the largest number that is a factor of both numbers.

so:

20: 10,5,4,2,1

36: 18,12,9,6,4,3,2,1

So, the greatest common factor of 20 and 36 is 4

Answer:

GFC: 4

Option B