Question: If a disease spreads at a rate of 10% per week, what will be the total percentage of the population infected after 3 weeks, assuming no recovery? (2021)
Options:
Correct Answer: 33%
Exam Year: 2021
Solution:
Total infected after 3 weeks = 10% + 10% of (100% - 10%) + 10% of (100% - 20%) = 10% + 9% + 8% = 27%.