One group and two groups 1. 18 people; A group of three groups 12 people; A group of 9 people, 4 groups; Six people in a group, six groups; A group of 4 people, 9 groups; Group of three, 12, group of two, 18.

2. Xiaogang is 7 years old and his younger brother 13 years old.

1.685040

2.2+ 19+29

5.58