How do you calculate the disease frequency rate in these problems

Question

1. The cumulative incidence rate in a population of 100,000 people where 9 new cases of disease were reported within 1 year
2. The prevalence of a chronic disease on November 1st where 9 initial cases were found in September with an additional 45 cases reported in October of a small city with a population of 75,000 people.
3. The relative risk of death from exposure A if the mortality rate in the exposed group is 60 deaths per 1000 person-years and the mortality rate in the unexposed group is 20 per 1000 person-year

Answer 1

1. nine cases per year: 9/100,000 per year

2. Really, not enough information, but since it is a chronic disease, so there is no information to believe it is changing: 27 cases/75000 per month

3. risk of death= 40 per/1000person-year