Can someone answer A & B questions in this photo I provided pleaseee

a. Participant 1 first showed symptoms Of flu on January 11, 2020 and remained symptomatic thereafter. What was this participant's share Of "time at risk" for flu? b. Participants 2 and 3: both of them first showed symptoms of flu on January 6, 2020 and remained symptomatic thereafter. What were their total "time at risk" for flu? Answer for a & b: During the period of observation (January of 2020), participant 1 was symptom free for10 days (Jan 1 through Jan 10). In other words, after being recruited into the study, this person was at risk for developing flu symptoms for 10 days. Thus, participant 1 was at risk for 10 person-days. Participants 2 and 3 were each at risk for 5 days, accounting for a total of 10 person-days. Refer to the figure below. Refer also to slides 15-16 in Module 3. Jan 1 Recruited into study Jan 11 (beginning of follow up) developed symptoms Figure 1: This person was at risk for 10 days, contributing 10 person-days (one person being at risk for 10 days) Jan 1 Jan 6 Recruited into study developed (beginning of follow up) symptoms Figure 2: Each of these two individuals was at risk for 5 days; each contributed 5 person-days. Together, they contributed 10 person-days