LSAT 138 | Section 4 | Logical Reasoning: Q5

LR Question 5 Explanation

QUESTION TEXT: Recent epidemiological studies report that Country X has…

QUESTION TYPE: Paradox

PARADOX: Country X has a lower rate of disease P, but people who have disease P are more likely to die.

ANALYSIS: On paradox questions, you must:

1. Figure out why the situation is confusing.
2. Figure out how to explain the confusion.

A lot of people skip step one. But you need to understand the confusion before you can explain it. Here, the confusion is that Country X seems to have both more and less of a problem with disease P.

As for the second point, a lot of people pick answers that are merely true, but explain nothing.

I thought of the answer in advance: “What if the reporting system sucks, so that only the most severe (and fatal) cases get reported?” Here’s a numerical example of how that might work:

• In the country of Reportistan, there are 1000 cases of disease P, and doctors have reported every since one. 10 people have died.
• In the country of Whocaresistan, there are 1000 cases of disease P, and 10 people died. But doctors only reported the 10 cases of death.

So in the second country, the disease seems rare but fatal. However, this is just a statistical illusion: the amount of disease P is the same in both countries.

___________

1. This explains nothing about the reporting rate or about deaths.
2. A tempting answer, but the paradox only refers to residents.
3. CORRECT. This resolves the paradox. Country X actually has a higher rate of disease P, but the reported rate is low. Since only the most fatal cases are diagnosed, the death rate per number of reported cases is high. (The death rate per number of actual cases might not be.)
4. So? The studies looked at overall incidence of disease P. Presumably they were able to take this fluctuation into account.
5. Other illnesses don’t matter. We’re only talking about disease P.