answer all questions with explanation

There are 400 people who were disease free before January 13, 2021. Ten people became sick on January 13. Of them, 8 recovered on or before January 18. The disease was so severe that one died after 3 days of illness. One continued to be ill until January 20. On January 20, 15 more people were sick and all of them except two continued to be sick until January 25. Calculate the following (express the rates per 1,000): a. Point prevalence on January 13 b. Period prevalence from January 13 to January 20 c. Incidence on January 20 d. Point prevalence on January 25