Talking about ages in task 1:
1. People from the 18-39 age group
2. People in the 18-39 age set
3. People aged from 18 to 39
4. Those aged from 18 to 39
5. People who are/were aged 18-39
6. 18-39 age group / category / bracket
7. Individuals within the 18 to 39-year-old range
8. 18 to 39 year olds
9. 18 to 39 year old people
10. People ages 18 and 39
11. People within the 18-39 demographics
12. The youngest age group / category
13. The oldest age group / category
14. Their younger / older counterparts
15. Their male / female counterparts aged 18-39
16. People belonging to the 18-39 age bracket
17. People aged between 18 and 39
18. People between the ages of 18 and 39
@Mukhiddinov_blog
1. People from the 18-39 age group
2. People in the 18-39 age set
3. People aged from 18 to 39
4. Those aged from 18 to 39
5. People who are/were aged 18-39
6. 18-39 age group / category / bracket
7. Individuals within the 18 to 39-year-old range
8. 18 to 39 year olds
9. 18 to 39 year old people
10. People ages 18 and 39
11. People within the 18-39 demographics
12. The youngest age group / category
13. The oldest age group / category
14. Their younger / older counterparts
15. Their male / female counterparts aged 18-39
16. People belonging to the 18-39 age bracket
17. People aged between 18 and 39
18. People between the ages of 18 and 39
@Mukhiddinov_blog