Answer:
9. 21 days = 3 weeks (7 days in a week)
10. 200 years = 2 centuries (100 years in a century)
11. 4 decades = 40 years (10 years in a decade)
12. 36 months = 3 years (12 months in a year)
13. 96 hours = 4 days (24 hours in a day)
14. 6 months = 26 weeks (52 weeks in a year divided by 2)
15. 2 weeks
16. 50 years
17. 65 days
18. 110 weeks
19. hours
20. months
21. centuries
22. years