#18 - Every delegate to the convention is a party member

[Administrator]

Complete Question Explanation

Must Be True—FL. The correct answer choice is (C)

This stimulus is comprised of three formal logic statements:

First, every convention delegate is a party member:

• delegate party member

Second, some delegates are government officials: Since “some” is a relationship that goes in both directions, this could be shown as:

• delegates officials

...or in the other direction:

• officials delegates

The first two statements can be linked as follows:

• officials delegates party member

(This leads to the inference that some officials are party members (specifically, the officials who are delegates).

The third statement is that each official at the convention is a speaker:

• official speaker

The third statement can also be linked to the second, as follows:

• delegates officials speaker

The linked statement above leads to the inference that some delegates are speakers (specifically, the ones who are officials).

Finally, all three statements can be linked together as follows:

• party member delegates officials speaker

The linked statements above lead to the combined inference that some delegate-party members are official-speakers.

The question that follows is a Must Be True question, so the correct answer choice will likely provide one of the inferences discussed above.

Answer choice (A): The author provides that every delegate is a party member:

• delegate party member

but that doesn’t mean that every party member is a delegate. The most that could be said from that side of the relationship is that some party members are delegates:

• party member delegates

Answer choice (B): The author provides no information about non-delegates or non-party members, so this choice cannot be confirmed by the stimulus and should be ruled out of contention.

Answer choice (C): This is the correct answer choice, as it provides that some speakers are delegates. Again, since the some relationship goes in both directions, this also provides that some delegates are speakers, an inference validly drawn from the linking of the author’s second and third statements.

Answer choice (D): The third statement in the stimulus is that each official at the convention is a speaker:

• official speaker

This allows the inference that some speakers are government officials, but it does not allow one to infer that every speaker at the convention is a government official.

Answer choice (E): As discussed, the linking of the first and second statements lead to the inference that some officials at the convention are party members. Since this choice goes well beyond “some,” to “every,” it cannot be confirmed by the information in the stimulus, fails the Fact Test, and should be ruled out of contention.

[maximbasu]

Hi,
I chose B while the correct answer is C.

My diagram looks like this:

speaker <---- Govt Delegate Party Member

I understand why C is correct but B also seems correct. Why is it wrong?

Rgs,
MB

[Adam Tyson]

Hey Maxim! If I had to guess, I would say that you are interpreting the word "some" to mean "at least one but not all". That may be so in common usage, but not on the LSAT. In LSAT-world, "some" includes ALL. If I say that some of the delegates are government officials, it allows for the possibility that they all are. It would be a completely true statement if I said "some human beings require air and water to live" because all do, and some includes all. That's not the way we talk in everyday life - when we mean all, we say all instead of some - but that is often the way we see things on the LSAT.

Now, all that aside, the some vs all issue really doesn't matter all that much in this case when we are evaluating answer B. Do we have any proof that there are speakers who are not delegates or party members? We know that all the delegates are party members, that some of the delegates are government officials, and all of the government officials are speakers - your diagram looks perfect to me. Where is the rule, though, that says not all speakers are members or delegates? Couldn't it be true that at least one speaker is not a government official, or a party member, or a delegate? Could these rules still apply and yet allow a speaker from some other group - say, a special guest speaker? While B COULD be true, this is a MUST be true question, so you have to prove it based on the info in the stimulus. What info proves B? None, I'm afraid.

Take another look, make sure you are not confusing the "some" concept or reading this as a Could Be True question, and see if it isn't easier now to eliminate B. If it still isn't clear, come back here for more help. We'll be here!

[c-erv]

Hello, I narrowed the answers to C and E and don't see why E is wrong

I also understand the problem
Speaker <--- Gov Off Delegate Party Member

If we look at E it reads; Gov Off Party Member

Based on my understanding of the formal logic, if we started at Gov Off we could ride the some train to Delegate and Delegate leads us to party member. Thus, wouldn't E be right?
Can someone please fill me in on what I'm missing here

Thanks

[Adam Tyson]

Thanks for the question, c-erv! You are right that we can ride that train from Govt to Delegate to Party, but along the way we have to take into account that it's "some" riding that train, not necessarily all. That's the problem with answer E - it claims that ALL the Govt folks must be party members, but we can only prove that SOME are (the ones who are Delegates). I can't make the leap that every Govt official is a Party member, because there could be one Govt official there who is NOT a delegate and therefore doesn't have to be a Party member.

Hope that helps!

[c-erv]

Yikes, sure does help. Completely forgot that we need to carry the Some over.
Many thanks!

[LawSchoolDream]

Complete Question Explanation

Must Be True—FL. The correct answer choice is (C)

This stimulus is comprised of three formal logic statements:

First, every convention delegate is a party member:

• delegate party member

Second, some delegates are government officials: Since “some” is a relationship that goes in both directions, this could be shown as:

• delegates officials

...or in the other direction:

• officials delegates

The first two statements can be linked as follows:

• officials delegates party member

(This leads to the inference that some officials are party members (specifically, the officials who are delegates).

The third statement is that each official at the convention is a speaker:

• official speaker

The third statement can also be linked to the second, as follows:

• delegates officials speaker

The linked statement above leads to the inference that some delegates are speakers (specifically, the ones who are officials).

Finally, all three statements can be linked together as follows:

• party member delegates officials speaker

The linked statements above lead to the combined inference that some delegate-party members are official-speakers.

The question that follows is a Must Be True question, so the correct answer choice will likely provide one of the inferences discussed above.

Answer choice (A): The author provides that every delegate is a party member:

• delegate party member

but that doesn’t mean that every party member is a delegate. The most that could be said from that side of the relationship is that some party members are delegates:

• party member delegates

Answer choice (B): The author provides no information about non-delegates or non-party members, so this choice cannot be confirmed by the stimulus and should be ruled out of contention.

Answer choice (C): This is the correct answer choice, as it provides that some speakers are delegates. Again, since the some relationship goes in both directions, this also provides that some delegates are speakers, an inference validly drawn from the linking of the author’s second and third statements.

Answer choice (D): The third statement in the stimulus is that each official at the convention is a speaker:

• official speaker

This allows the inference that some speakers are government officials, but it does not allow one to infer that every speaker at the convention is a government official.

Answer choice (E): As discussed, the linking of the first and second statements lead to the inference that some officials at the convention are party members. Since this choice goes well beyond “some,” to “every,” it cannot be confirmed by the information in the stimulus, fails the Fact Test, and should be ruled out of contention.

Can formal Logic Some statements be reversed like that? Is that only for MOST and SOME? Because All or None would be one way arrow, correct?

[Chandler H]

Hi LawSchoolDream,

I'm not sure exactly what you mean, but to answer your question, you're right that all SOME statements can be reversed. Let's use a simpler example:

All squares are rectangles, but only some rectangles are squares.

This is true, because "rectangle" is a larger category that includes "square." However, it is still technically true to write that R SQ and SQ R—you can reverse the SOME statement, even if it's not the full pictures. Some squares are rectangles, because ALL squares are rectangles.

Does this make sense?