What is your answer?

    Some cave dwellers use fire.
    All who use fire have intelligence.
    So ???
    { 1 } - All who have intelligence use fire.
    { 2 } - Some cave dwellers have intelligence.
    { 3 } - All cave dwellers have intelligence.
    { 4 } - None of these validly follows.

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1 is wrong. Please try again.

    Some cave dwellers use fire.
    All who use fire have intelligence.
    So ???

This is invalid (try plugging in "calculus" for "..."):

    All who use ... have intelligence.
    So all who have intelligence use ....

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2 is correct!

    Some cave dwellers use fire.
    All who use fire have intelligence.
    So ???
    { 1 } - All who have intelligence use fire.
    { 2 } - Some cave dwellers have intelligence.
    { 3 } - All cave dwellers have intelligence.
    { 4 } - None of these validly follows.

Right! If SOME of them use fire, and ALL who do this have intelligence, then SOME of them have intelligence.

It might be that they ALL have intelligence. But we can't conclude this from the premises, since we only know that SOME of them use fire.

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3 is wrong. Please try again.

    Some cave dwellers use fire.
    All who use fire have intelligence.
    So ???
    { 1 } - All who have intelligence use fire.
    { 2 } - Some cave dwellers have intelligence.
    { 3 } - All cave dwellers have intelligence.
    { 4 } - None of these validly follows.

"All" in the conclusion is too strong. Maybe only a few cave dwellers use fire -- and only these few have intelligence.

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4 is wrong. Please try again.

    Some cave dwellers use fire.
    All who use fire have intelligence.
    So ???
    { 1 } - All who have intelligence use fire.
    { 2 } - Some cave dwellers have intelligence.
    { 3 } - All cave dwellers have intelligence.
    { 4 } - None of these validly follows.

No, we can draw a conclusion.

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the end