LSAT 103 | Section 3 | Logical Reasoning: Q18

LR Question 18 Explanation

QUESTION TEXT: A stingray without parasites is healthier than it…

QUESTION TYPE: Paradox

PARADOX: An individual stingray is better off without parasites. But if stingrays don’t have parasites, their environment is in trouble, thanks to pollution.

ANALYSIS: This hardly seems like a paradox. It sounds like parasites are particularly vulnerable to environmental pollution, and die first…they are like canaries in a coal mine.

This doesn’t change the fact that parasites are bad for individual stingrays.

Three of the four wrong answers don’t even mention pollution. That’s bad. It’s fine for the right answer to mention something that wasn’t in the stimulus, but they always have to affect the stimulus somehow.

___________

1. CORRECT. This explains it. Parasites are vulnerable to pollution because some of their hosts die. So parasite deaths are a warning sign that Stingrays’ environments are in trouble, even if the Stingrays become individually healthier without parasites.
2. I’m not sure what a stingray’s feeding habits have to do with parasites and pollution.
3. This explains why stingrays are less healthy when they have parasites. But it doesn’t explain anything about pollution.
4. This is one definition of a stressed ecosystem. That’s nice. We don’t know if this is the only definition, and we have no idea what this has to do with Stingrays and parasites. We’re never told how many species live in the Stingrays’ ecosystems.
5. This explains why Stingrays don’t necessarily die when they have parasites. Then the parasites would be in trouble. But it tells us nothing about pollution.

Recap: The question begins with “A stingray without parasites is healthier than it”. It is a Paradox question. Learn more about LSAT Paradox questions in our guide to LSAT Logical Reasoning question types.