PT28.S3.Q16 - historian: we can learn about

tanes256

Hey, y'all! I'm having a tough time negating some AC for NA. For AC A and B they don't seem to be negated the same.

A. None of the mercury introduced into the body can be eliminated.

Negated: some of the mercury introduced into the body can be eliminated.

B. Some people in Beethoven's time did not ingest mercury.

Negated: all people in Beethoven's time ingested mercury.

Why was there no "not" included in A but "not" was removed from B when negated? I know you can add the phrase, "it is not the case" before the AC instead of trying to negate certain words but that doesn't work for me. For some reason it doesn't make sense to me.

https://7sage.com/lsat_explanations/lsat-28-section-3-question-16/

Sami

I think its more helpful to see negation as something that logically divides the statement neatly in two halves.

Answer choice A:
Another way to read this answer choice is, all mercury introduced into the body does not get eliminated. We know All means 100%. The logical opposite of All (100%) is "some not (0%-99%)".

When applied to this answer choice it would read: some mercury introduced into the body does not not get eliminated. In other words, some mercury introduced into the body gets eliminated.

This lesson should help see how this occurs. https://7sage.com/lesson/advanced-negate-all-statements/

Answer choice B says:
B. Some people in Beethoven's time did not ingest mercury.

The logical opposite of "Some (1-100%)" has to be None (0%). So this statement would now read:
None of the people in Beethoven's time did not ingest mercury. In other words: All of the people in Beethoven's time ingested mercury.

This is akin to saying: None of the dogs do not bark. It means all dogs bark.

I hope reading this and reviewing the core-curriculum helps.

But I think you could be having trouble seeing what these sentences actually mean logically. For example, answer choice A -none of the mercury introduced into the body can be eliminated- is a bit tricky because you have to see that this is saying all mercury introduced into the body does not get eliminated. The words "none" translates to negating the necessary condition (group 4) which in this instance would mean you have to negate "gets eliminated".

Then for answer choice B you have to see that while negating some would mean none and the word "None" again acts as negating necessary (Group 4) making the negation of the sentence positive.

*So I think you also maybe having issues just recognizing when group 4 indicators are occurring in sentences and how to translate them.

I hope this was helpful. Let me know if you have any more questions.