LSAT 8 | Section 4 | Logical Reasoning: Q10

LR Question 10 Explanation

QUESTION TEXT: A distemper virus has caused two-thirds of the seal…

QUESTION TYPE: Necessary Assumption

CONCLUSION: The pollution of the North Sea weakened the immune system of the seals. This caused them to become very vulnerable to the distemper virus.

REASONING: There must have been a reason the normally latent (passive) virus could act so suddenly.

ANALYSIS: This argument assumes a lot of things. Mainly it assumes that all alternate explanations are wrong. The right answer provides an alternate explanation.

___________

1. This isn’t necessary to the claim that pollution suddenly caused recent deaths.
2. What happened after May 1988 is irrelevant. The seals were already dead.
3. CORRECT. Yes. If this were true then pollution may not have been necessary to allow the virus to win.
4. Why would this be necessary? The stimulus argues that North Sea pollution is severe.
5. This would support the argument. But it isn’t necessary: the seals’ immune systems could have been weakened even if other species didn’t die.

Recap: The question begins with “A distemper virus has caused two-thirds of the seal”. It is a Necessary Assumption question. Learn more about LSAT Necessary questions in our guide to LSAT Logical Reasoning question types.