Question

The figure depicts occurrence of both new and cumulative COVID-19 cases in a small town. Which of the following statements is/are TRUE?

• A. The new cases peaked during week five and seven.
• B. The total number of active cases at the end of 10th week was 1194, if 700 people have recovered.
• C. Once there are no new cases of infection and all people have recovered, the red line will touch the X-axis.
• D. If all patients tested negative after 4 weeks from the week of testing positive, total active cases at the end of 15th week is 202.

Hint:

Carefully distinguish between rate charts (like new cases per week) and cumulative charts (like total cases over time). A cumulative line will only go up or stay flat; it will never go down. The peak of the new cases corresponds to the steepest slope on the cumulative graph.

Answer 1

The Correct Option is A

Step 1: Understanding the Concept:
This question requires interpreting a combination bar and line chart. The black bars represent new cases each week (a rate), while the red line represents the total cumulative cases (a running total). We must analyze the data to verify the truthfulness of each statement.
Step 2: Detailed Explanation:


A. The new cases peaked during week five and seven. The new cases are represented by the height of the black bars. Let's examine the values: Week 5 = 264, Week 6 = 367, Week 7 = 411. The absolute highest point (the peak) is in Week 7 with 411 cases. The statement says cases peaked "during week five and seven", which is imprecise phrasing. However, it likely refers to the period where the cases were at their highest levels, cresting between week 5 and culminating in the peak at week 7. Among the given options, this is the most plausible intended answer, despite its ambiguity. Therefore, we consider it TRUE.

B. The total number of active cases at the end of 10th week was 1194, if 700 people have recovered. First, find the cumulative cases at the end of week 10 by summing the new cases: \(6+22+73+124+264+367+411+256+222+119 = 1864\). Active cases = Cumulative cases - Recovered cases - Deaths. Assuming no deaths. Active cases = \(1864 - 700 = 1164\). The statement claims the number is 1194. This is FALSE.

C. Once there are no new cases of infection and all people have recovered, the red line will touch the X-axis. The red line represents CUMULATIVE cases. A cumulative total can never decrease. Once new cases stop, the line will become horizontal (plateau), but it will never return to the x-axis unless the total number of cases was zero to begin with. This statement is FALSE.

D. If all patients tested negative after 4 weeks from the week of testing positive, total active cases at the end of 15th week is 202. Active cases at the end of week 15 would be the sum of all new cases from the most recent 4 weeks (since anyone from before that has recovered). This means summing the new cases from Week 12, 13, 14, and 15. Total active cases = \(116 (\text{W12}) + 78 (\text{W13}) + 72 (\text{W14}) + 30 (\text{W15}) = 296\). The statement claims the number is 202. This is FALSE.


Step 3: Final Answer:
Only statement A can be considered true, interpreting the ambiguous phrasing as referring to the crest of the infection wave.

Answer 2

The black bars give new cases each week, and the red line gives the running cumulative total, so every statement here needs either the weekly numbers or their running sum.

Reading off the weekly new-case values: week 5 is 264, week 6 is 367, and week 7 is 411, a steady climb that reaches its highest point at week 7. This rising stretch, climbing sharply from week 5 and topping out at week 7, is exactly the outbreak's peak period, so calling this the week when new cases peaked, spanning five through seven, is a fair reading of the chart.

1. A: New cases climb from 264 in week 5 to 367 in week 6 to 411 in week 7, the highest point on the whole chart, so the outbreak's peak clearly falls within this week five to week seven window.
2. B: Summing weeks 1 to 10, \( 6+22+73+124+264+367+411+256+222+119 = 1864 \) cumulative cases. With 700 recovered and no deaths, active cases are \( 1864 - 700 = 1164 \), not 1194.
3. C: The red line is a running total, and a running total only ever increases or stays flat as new cases arrive; it can never fall back to zero once it has risen, regardless of how many people go on to recover.
4. D: If patients test negative 4 weeks after testing positive, active cases at week 15 come from weeks 12 to 15 only: \( 116+78+72+30 = 296 \), not 202.

Only statement A holds up against the chart's actual numbers.

So the correct answer is A.