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June 2010 LSAT Section 5 Question 18

Based on the passage, it can be concluded that the author and Broyles-González hold essentially the same attitude toward

Deke on June 9, 2018

“Not all” statements

You mentioned that LSAC considers some and most to be possible to actually be all, would it therefore follow (you didn't mention it in the video) that not all could also be zero, and not then swappable with some when reversing? Eg. I have 4 glass containers made by xyz corp, none of them have 4mm glass, so i know for a fact not all xyz corp glass is 4mm thick, but i can't be sure any at all is 4mm thick. Is this a proper LSAC rule, or have i overthought this?

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Deke on June 9, 2018

(And then NOT swappable with some when reversing)

Christopher on June 10, 2018

@Deke, I do think you may be overthinking it a bit.

Let's take the glasses concept by say there are 100 glasses by xyz. We know nothing about the 100 glasses except that there are 100. If we measure 4, and they are all 4mm thick, then we can say "some are 4mm." If we measure 51, and they are all 4mm this, then we can say "most are 4mm." It is possible that ALL of the 100 glasses are 4mm thick, but we cannot know that from the information we have.

Similarly, if we measure 4 glasses which are not 4mm thick, we can conclude that "some are not 4mm." If we measure 51 that are not 4mm thick, we can say "most are not 4mm." Again, it is possible that ALL are not 4mm, but we cannot know that with the given information.

However, if we KNOW that NONE of the 100 glasses are 4mm thick, then it no longer becomes an issue of some/most but an issue of all/none. So rather than "xyz glasses - some/most - not 4mm" it would be "xyz glasses ==> not 4mm."

Does that make sense?

Deke on June 10, 2018

Yes, thank you, i read that for the test it is best to fold my idea of "not all" back into "some/most are not", which of course still allows for zero in the same manner as some/most allows for 100%.