Question: what is the greatest common factor of 36 and 60?
Answer: Factors of 36 are {1,2,3,4,6,9,12,18,36} . Factors of 60 are {1,2,3,4,5,6,10,12,15,20,30,60} . Common factors are }1,2,3,4,6,12} . Hence Greatest Common Factor is 12 .