Logical ReasoningDifficulty: Easy

PT15 S2 Q6 Explanation

A primate jawbone found in Namibia

A free, expert breakdown of this official LSAT Logical Reasoning question.

TopicsNecessary Assumption

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Stimulus

A primate jawbone found in Namibia in southern Africa has been identified by anthropologists as that of an ape that lived between 10 million and 15 million years ago. Researchers generally agree that such ancient primates lived only in dense forests. Consequently, the dry, treeless Namibia must have replaced an earlier, heavily forested terrain.

What this question is testing

Necessary Assumption

Your task

Find the assumption the argument requires in order for its conclusion to hold.

Common trap

Answers that would help the argument but aren't strictly required (sufficient, not necessary).

Winning move

Negate each choice — the right one breaks the argument when negated.

Reading along? Open the full official question in LawHub — we show a fragment here and keep the reasoning in our own words.

The question
6.

The argument assumes which one of

Answer choices

  1. Trap4% picked this

    Modern apes also tend to live only in heavily

  2. Correct85% picked this

    The ape whose jawbone was found lived in or near the area that

    Why this is right

    Answer B is correct.

    Skill tested: Necessary Assumption · how this choice captures the argument's function is the move to repeat next time.

  3. Trap6% picked this

    There were no apes living in the area that is now Namibia prior to 15

  4. Trap2% picked this

    The ape whose jawbone was found was adapted to a diet that was significantly different from that

  5. Trap3% picked this

    The ancient primates were numerous enough to have caused severe damage to the ecology of the forests

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