Activist: Any member of the city council ought either to vote against

(D) If not every member of the city council abstains in the vote on the proposal, the matter will not be decided by the city’s voters.

I originally crossed D because it's saying that if you asked every member of the city to not abstain (vote against) then the city's voters will not have the right to decide, but the stem say that at least one member of the city council should vote against the proposal so one vote from the member of the city is sufficient to not let the the city's voters decide.

By POE, B is correct, but I agree that B is not an assumption

How can B be an assumption - it sounds more like a conclusion.

B is more intent than assumption. Do we have correct OA here ? Isn't Not Every = At Least 1 ? Option D seems more assumption-like.

GMATNinja generis VeritasKarishma MentorTutoring AjiteshArun

Why is B correct here??

Premise : Council members can vote in favor or against
Counter Premise : If they don't, then it goes to City people who i believe will reject
Conclusion : so the author wants at least one to vote

Author's assumption : City people will reject, should not be allowed to vote
Author does not want City people to vote as according to hmim they will reject, so assumption will follow logically if city people are not allowed to vote.

Hence B

Hi warrior1991,

Let's take a (somewhat) similar situation, a quiz competition:
1. Any member of our team should answer, or not answer, the question posed to our team.
2. If every member of our team fails to answer the question posed to our team, the question passes to the next team.
4. Therefore, at least one member of our team should answer the question posed to our team. ← This is the conclusion.

The question asks us for a statement (3), an assumption that would help us plug the gap between (1) & (2) and (4).

1. Any member of our team should answer, or not answer, the question posed to our team.
2. If every member of our team fails to answer the question posed to our team, the question passes to the next team.
3. We should not allow the question posed to our team to pass to the next team.
4. Therefore, at least one member of our team should answer the question posed to our team.

Now the conclusion looks better. Why should we avoid a situation where no one on our team answers the question? To keep it from being passed to the next team. That's why at least one team member should answer the question.

I agree with what AjiteshArun has written above, and I would not have thought to express the justification of (B) in such a way. As for (D), it presents, in mathematical or formal logic terms, the inverse of the given conditional statement. A bit more on that first:

Conditional Statement: If A, then B.
Inverse: If not A, then not B.
Converse: If B, then A.
Contrapositive: If not B, then not A.

These relationships may be useful to know for such questions, even if they are not strictly necessary to keep in mind for GMAT™ CR questions. In the question at hand, our conditional statement is as follows:

If all the members abstain, the matter will be decided by the city’s voters.

Choice (D) negates this, creating a could-be-true situation, rather than a must-be-true assumption that we are seeking:

If not every member of the city council abstains in the vote on the proposal, the matter will not be decided by the city’s voters.

Such a consideration goes beyond the scope of the passage. For all we know, one member of the council could vote for the proposal and another against, with the rest abstaining, and with a deadlock resulting from the council voting phase, the matter could still be decided by the voters of the city. We can only speculate. Looking at (B) again, given the constant presence of "proposal language," as I will call it—ought to, should—we can deduce that, to the activist, it is only reasonable to assume that the proposal should not be decided by the city's voters.

I hope that helps.

- Andrew

First note that it is an LSAT question. It asks for "conclusion of the activist’s argument follows logically if which one of the following is assumed"

We are not looking for an assumption as defined in GMAT. We are looking for a "sufficient premise", not a "necessary premise".

Activist:
- Any member of the city council ought either to vote against the proposal or to abstain.
- But if all the members abstain, the matter will be decided by the city’s voters.

Conclusion: So at least one member of the city council should vote against the proposal.

When will the conclusion follow? When we say "but the city's voters should not decide the matter". So at least one member of city council should vote against.

- Any member of the city council ought either to vote against the proposal or to abstain.
- But if all the members abstain, the matter will be decided by the city’s voters.
- The proposal should not be decided by the city’s voters.
Conclusion: So at least one member of the city council should vote against the proposal.

Makes complete sense, right? No gaps in logic.

(D) If not every member of the city council abstains in the vote on the proposal, the matter will not be decided by the city’s voters.
This means if even one member votes, the matter will not be decided by the city's voters.
Note that this is the flip side of our second premise above. If all members abstain, city voters will decide. If even one member votes, city voters will not decide. What is still missing is that "city voters should not be allowed to decide" to reach our conclusion "at least one member must vote". Hence this is not the answer.

Answer (B)

What if some city council member votes in favor then conclusion will be distorted.( negate)
So is it not necessary that no council member vote against in favor. why can not this be an assumption?

Is C wrong because it doesn't mention about vote against or abstain on which the conclusion directly depends.
C is out of scope?

Please suggest. VeritasKarishma MentorTutoring AjiteshArun

Yes, choice (C) is out of scope. As VeritasKarishma mentioned above, the question stem is asking us to put a finger on an assumption that allows the argument to "follow logically." There seems to be a disconnect if we attempt to justify (C) as a necessary assumption that leads to the argument. Try it out. In the vein of what AjiteshArun has done above, where would you place the sentence to create such a logical progression of ideas, given that the first and last lines are fixed? (The first line is fixed because it introduces the idea of voting on the proposal; the last line is fixed because it is the argument itself.)

Version 1:
1) Activist: Any member of the city council ought either to vote against the proposal or to abstain.
2) No members of the city council will vote in favor of the proposal.
3) But if all the members abstain, the matter will be decided by the city’s voters.
4) So at least one member of the city council should vote against the proposal.

The activist is giving a recommendation, not assessing how council members will actually vote. The second sentence seems out of place.

Version 2:
1) Activist: Any member of the city council ought either to vote against the proposal or to abstain.
2) But if all the members abstain, the matter will be decided by the city’s voters.
3) No members of the city council will vote in favor of the proposal.
4) So at least one member of the city council should vote against the proposal.

Again, the proposed assumption breaks up the linear logic that leads to the argument. Notice that what is now sentence 2 operates within a conditional (if-[then]) statement, so it is presenting a hypothetical scenario. Sentence 3, on the other hand, is definitive, not to mention that reading 3) and 4) back to back leaves me scratching my head. (How does the argument necessarily follow from the previous sentence? The ideas seem to be going in different directions, and 3) only seems to be interrupting.)

I hope that helps. If not, you seem to have three Experts willing to chime in on this one.

- Andrew

Thanks for the explanation.

So do you mean to say that option B is bridging the gap firmly than is option D??

Hi warrior1991,

Let's take another look at the question stem:
The conclusion of the activist’s argument follows logically if which one of the following is assumed?

This question is asking us to provide an assumption that would plug the logical gap between the support and the conclusion. The basic situation is a little bit like "if we do X, Y won't happen. So we should do X". But why? Why should we stop Y from happening?

In the quiz example, this is the argument that D would lead to:
1. Any member of our team should answer, or not answer, the question posed to our team.
2. If every member of our team fails to answer the question posed to our team, the question passes to the next team.
3. If not every member of team abstains, the question will not pass to the next team.
4. Therefore, at least one member of our team should answer the question posed to our team.

But this leaves us no closer to plugging that gap we identified. Why exactly should at least one person answer the question? Why is that so important? For example, what if there are negative points for answering incorrectly, and answering a question incorrectly is worse than letting the next team take a shot at the question? The situation in the question is the same. We can do something to stop voters from deciding the issue. But that alone does not tell us why we should do that something. The correct option tells us that voters should not be allowed to decide on the proposal, and that gives us a reason to take the action advocated by the conclusion.

I hope the quiz example helped, but I'll drop it so that we can focus on the original question, more directly addressed by this post and this post.

(A) If all the members of the city council abstain in the vote on the proposal, the city’s voters will definitely decide in favor of the proposal.
-When you see extreme language, you should get suspicious, because a choice with extreme language is almost never correct on the GMAT.

(B) The proposal should not be decided by the city’s voters.
- logically correct fills the gap in the argument.

(D) If not every member of the city council abstains in the vote on the proposal, the matter will not be decided by the city’s voters.
- here, we need to ask, is this really helping us bridge the gap in the argument? keep in mind assumptions are unstated premises. we NEED the assumptions to be true for the argument to stand.

IMO the city people get to decide when there is no result achieved by the council. This can happen in two ways.
1. No one in the council votes.(given in passage)
2. Equal votes in favor and against.(not given in passage but follows logically)
Thus D is out. B is correct.

[size=80][b][i]Posted from my mobile device[/i][/b][/size]

Hi all,

Just out of curiosity, is B both a sufficient AND necessary assumption? If we negate B, then there won't be any reason for the conclusion to hold true. Thank you.

An assumption bridges the gap between premise and conclusion. Here there is a sentence missing between the premise and the conclusion that the at least one vote should be against the proposal so that the city voters don't vote. That sentence is option B- The proposal should not be decided by the city’s voters, a statement that bridges the gap and hence is the assumption.

Note that the question is specifically asking what is necessary for the conclusion to follow, if you negate option B- The proposal can be decided by the city voters, the conclusion doesn't follow.
A-There is no way to know what the city's members will decide
C- Out of Scope
D- Wrong, only one member needs to vote against
E- Out of Scope