Sufficient and Necessary Diagramming Drill - Lesson 2 HW

[jessicamorehead]

Hi there,

I understand how to identify the sufficient and necessary components of a conditional statement. However, I am having trouble doing so when negative words are added to the sentence. For example, in lesson two's homework on sufficient and necessary diagramming pg 2-38, "3. No electrician is an architect" vs "4. If you are not an electrician, then you must be an architect." I understand the second statement as E crossed out because of the "not" --> A. But for the first statement, how do you know that the "no" is applied to the A side and not the E side of the arrow?

Additionally, I had a hard time when any conditional statement started with "No person/one/company etc." Example problems include:

Number 16. "No one has the right to address the council except for the chairman." I understand that the "except" is part of the "unless equation," but how to a negate the "no one?" Or is that not necessary?

Number 18. "None but the proud is arrogant." How do I distinguish which is sufficient and which is necessary?

Number 21. "Buying scalped tickets is the only way for Jim to get into the concert." I know "only" is used for the necessary side of the conditional statement, but why is "buying scalped tickets" on the necessary side?

Number 22. "No one in the Latin department is disallowed from teaching multiple classes this semester." I got very confused by the no one and disallowed portions of this statement. Please help clarify how to distinguish the sufficient and necessary portions of the statement!

Number 26. "No large corporation in Springfield will fund the community street fair." I thought the "No" applied to the "Large corporation" part of the sentence, but it does not. How do I know that the "No" is applied to the "Fund community street fair" portion?

PLEASE HELP!!

[Adam Tyson]

Hey there Jessica, thanks for your question! It's an important one, as these constructions that you have brought up can cause a lot of confusion. Most of these concepts were addressed in this blog post:

http://blog.powerscore.com/lsat/beyond- ... n-the-lsat

I encourage you to read it!

I'll supplement that post with this advice - try paraphrasing. See if you can turn the statement in question into a simple "if-then" statement, without changing the meaning of the original statement. For example, if you have the right to address the council, what do you know? You know that you are the chairman! What would happen if I tried the "if" the other way around, and started with "if you are the chairman" - would I know that you have the right to address the council? That's not as clear, and appears to change the meaning of the original claim. We don't know that the chairman has the right, just that nobody else does.

The blog post should make it clearer, and gets into things like using the unless equation coupled with those words of negation. Let us know if that doesn't clear it up for you, in which case we'll dig deeper for you.

Good luck!