https://sites.google.com/mail.csuchico.edu/lbstmath/math-210/chapter-8-number-theory/8-1-and-8-5-factors-and-multiples So, the common factors of 12 and 30 are: 1, 2, 3 and 6. It is a common factor ... The multiples of 5 are: 5,10,15,20,25,30,35,40,45,50,... Notice that ...