- Ư(6)={1,2,3,6}; Ư(20)={1,2,4,5,10,20};ƯC(6,20)={1,2}
- Ư(6)={1,2,3,6}; Ư(20)={1,2,4,5,20}; ƯC(6,20)={1,2}
- Ư(6)={1,2,3}; Ư(20)={1,2,4,5,10,20}; ƯC(6,20)={1,2}
- Ư(6)={1,2,4,6}; Ư(20)={1,2,4,20};ƯC(6,20)={1,2,4}