wha is the greatest common factor of 56 and 80?

Ans:
Factors of 56 are 1,2,4,7,8,14,28 and 56
Factors of 80 are 1,2,4,5,8,10,16,20,40 and 80
"Common" factors are those numbers which are factors of both 56 and 80, and
therefore appear in both the lists
i.e. 1,2,4,8
What is the "greatest" common factor? Obviously 8.
:)