Answer:
1. we see 80% of healthy people develops CVD
let healthy people be x, time t(in yrs) and infected people = y, z= no of healthy people left that year
t x y z
1 100 80 20
2 120 96 24
3 124 100 24
4 124 100 24
5 124 100 24
6 124 100 24
7 124 100 24
8 124 100 24
9 124 100 24
10 124 100 24
at last only 24 were left not having disease
Cumulative incidence of CVD = 1000-24 = 976
2. Prevalence of CVD at baseline = 80/100 = 0.8 = 80%
3. Prevalence of CVD at 10 years = 976/1000 = 0.976 = 97.6%