LSAT 150 | Section 2 | Logical Reasoning: Q2

LR Question 2 Explanation

QUESTION TEXT: Ancient humans in eastern North America hunted mammoths until…

QUESTION TYPE: Necessary Assumption

CONCLUSION: The human settlement in eastern North America existed at the time that mammoths lived in the same area.

REASONING: Humans hunted mammoths in eastern North America until mammoths vanished. We found a bone with an engraving of a mammoth at the ancient settlement.

ANALYSIS: This sounds like a good argument. But, consider my parallel argument: We found a bone with an engraving of a mammoth at the NYC museum of natural history. So clearly, mammoths live in NYC!

What the argument ignores is that the bone might be a cultural artifact, made many generations before the settlement existed.

Note: The bone in this question is not necessarily a mammoth bone. It’s an engraving of an image of a mammoth, on a bone.

___________

1. CORRECT. If the engraving was made before the settlement was occupied, then maybe mammoths were extinct when the settlement was created.
    
   e.g. Mammoths extinct 13000 years ago. Bone engraved 13500 years ago. Settlement founded 12000 years ago. (Therefore, bone handed down for 1500 years)
   Negation: The engraving was made before the settlement was occupied.
2. This would weaken the argument if true! We’re trying to prove mammoths were present.
3. This is irrelevant. We only care about whether mammoths existed in this specific part of North America.
4. It doesn’t matter if the engraving is unique. The engraving is only important because it shows humans had seen mammoths at some point prior to making the engraving.
5. This just makes the situation more confusing. We want to date the bone!

Recap: The question begins with “Ancient humans in eastern North America hunted mammoths until”. It is a Necessary Assumption question. Learn more about LSAT Necessary questions in our guide to LSAT Logical Reasoning question types.