SPM – MCQ 134 – Prevalence calculation

If prevalence of diabetes is 10%, the probability that three people selected at random from the population will have diabetes is:
A. 0.01
B. 0.03
C. 0.001
D. 0.003

Correct answer : C. 0.001

Prevalence of diabetes = 0.1
Probability that any one person selected from the population will have diabetes = 0.1
Probability that 3 people selected from the population will all have diabetes = 0.1*0.1*0.1 = 0.001