LSAT Prep Concept: Sufficient & Necessary - No As are Bs

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Hello my LSAT prep friends. As we are just over a month away from the June exam, I thought we should have a quick refresher on one of the many forms of Sufficient & Necessary sentences that pop up on the exam: “No As are Bs.” Many students think that this translates to: "If not A, then B." That is incorrect!

No As are Bs,” becomes “ If A, then not B.”

Example: No one that works at Betty’s Ice Cream Parlor, works on Sundays.

We read this as: If you work at Betty’s Ice Cream Parlor, then you do not work on Sundays.

Diagram:

WBIP ==> not WS

WS ==> not WBIP

Think about it this way, the example sentence isn’t saying those people who don’t work at the ice cream parlor work on Sundays. We do not know anything about people who don’t work at the ice cream parlor. Let’s try another.

Example: None of the sorbets at Betty’s Ice Cream Parlor have dairy in them.

Rewrite: If it’s a sorbet from Betty’s Ice Cream Parlor, then it does not have dairy.

Diagram:

SBICP ==> not D

D ==> not SBICP

Many students forget that “None of A is B” is the same as “No A is B.” You want to focus on what the sentence is saying, rather than the precise formula of the sentence. When the sentiment of the sentence is that “none of something” has a characteristic, we will be using the “No A is B” form.

Let’s try one more!

Example: Nobody with a morning shift at Betty’s Ice Cream Parlor will end up closing the shop.

Rewrite: If you have a morning shift at Betty’s Ice Cream Parlor, then you will not end up closing the shop.

Diagram:

MSBICP ==> not CS

CS ==> not MSBICP

The key is in understanding what the sentence is saying. Don’t get lost in robotically following formulas. The formula is there to help guide you, but you need to make sure to first and foremost understand what the stimulus is saying.

Hope that was helpful! Keep working hard on your LSAT prep. You’re almost there!

Happy Studying!

Naz signature Updated on Aug 18, 2016