common factor

Question

Gordon is campaigning for class president and plans to distribute some campaign materials: 8 flyers and 20 buttons. He wants each classroom to receive an identical set of campaign materials, without having any materials left over. What is the greatest number of classrooms Gordon can distribute materials to?

Answer 1

8=2*2*2; 20=2*2*5. Highest common factor is 2*2=4.

In 4 classrooms, we can have 2 flyers and 5 buttons in each. This makes 28 materials altogether.