Consider a class with 100 enrolled students. None of the students were ill at the beginning of the school year. On September 30, a total of 5 students reported having gastroenteritis. All 5 continued to be ill on October 1, but all 5 recovered within 3 days. On October 14, another 3 students developed gastroenteritis. All of these students continued to be ill on October 15, but all 3 recovered 5 days later. In this example, assume that a person cannot get gastroenteritis more than once.

1. Calculate the prevalence of gastroenteritis in the class on October 1(2 points)
2. Calculate the prevalence of gastroenteritis in the class on October 30 (2 points)
3. Calculate the cumulative incidence of gastroenteritis in the class during the month of October. (2 points)