Here we have a strengthen with necessary premise question. Remember that a premise is necessary for a conclusion if the falsity of the premise guarantees or brings about the falsity of the conclusion. First we check to see if the answer choice strengthens the passage, and then, if it does strengthen, we negate the answer choice to see if its negation makes the argument fall apart. If the answer choice does both those things then it is our correct answer.
Conclusion: "It follows that the pet lovers were voted down on their proposal by the majority of the tenants."
Why? We are told that a group of pet lovers tried to change the rule in their residential building that no pets are allowed, but they failed. We know that the policy to change a rule is that if the proposed change is to be put to a majority vote of all the tenants in the building, then the group of tenants has obtained the signatures of 10% of the tenants on the petition to change the rule. (Note: we write it this way because "only if" introduces the tenants obtaining 10% of the signatures of the tenants, and we know that "only if" is a necessary condition indicator.)
Thus, we diagram the policy like so:
PMV ==> OS10% not OS10% ==> not PMV
Well, where is the gap in reasoning? We know that the tenants' proposal failed. That means that they either didn't get a majority vote or they didn't get enough signatures. Remember, getting enough signatures is the necessary condition for putting the new rule to a majority vote.
Now, let's look at answer choice (A): "The pet lovers succeeded in obtaining the signatures of 10 percent of the tenants on their petition."
Does this strengthen? Yes.
We know, from the information in the passage, that there are two options on how the tenants proposal would fail: (1) they did not receive a majority vote and (2) they did not get enough signatures.
Answer choice (A) tells us that the pet loving tenants did--in fact--obtain enough signatures. Therefore, our conclusion is supported, i.e. this strengthens the conclusion that the pet lovers did not obtain a majority of votes.
Negation of (A): The pet lovers did not succeed in obtaining the signatures of 10% of the tenants on their petition.
Does this make the argument fall apart? Yes.
We see from our contrapositive that if the tenants did not receive enough signatures, then the new rule proposal was not even put to a majority vote. Thus, the conclusion cannot stand, since you cannot say that the pet lovers were voted down on their proposal by a majority of the tenants, when no such majority vote occurred.
Let us know if you have any specific questions about a certain wrong answer choice and we'd be happy to go over that answer choice with you!
Hope that clears things up! Please let us know if you have any other questions.
rolltribeSeptember 1, 2015
I think he wanted E explained as well as A, I would too.
NazSeptember 1, 2015
Remember, we are first looking for an answer that strengthens.
Does answer choice (E) strengthen the argument? No.
If the failure of the pet lovers to obtain the signature of 10% of the tenants on their petition for rule change guarantees that the rule change will be voted down by a majority of the tenants, this does not necessarily affect our argument. We do not know whether the tenants received 10% or not. In this scenario, they could have not received 10%, which means - according to the passage - the issue would not have been put to a majority vote (since the building's regulations state that only if a group of tenants can obtain the signatures of 10% pf the tenants on a petition to change a rule will the proposed change be put to a majority vote of all the tenants in the building).
We must take the premises in the passage to be true. So, according to this building regulation, answer choice (E) cannot stand, since we know that when there is a failure to obtain signatures of 10% of the tenants, then the proposed change will not even be put to a majority vote, i.e. it cannot fail to receive a majority of the votes if it never gets put to a vote in the first place.
Thus, answer choice (E) is not the correct answer.
Hope that clears things up! Please let us know if you have any other questions.
kaori-watanabeAugust 3, 2018
I am confused...
The group of pet lover failed to change the rule.
That means that the group could not obtain 10 % of of the tenant on a petition to change the rule.
Nevertheless, the answer is A?
What am I missing? could you help me?
AnitaAugust 4, 2018
@kaori-watanabe What we know is tenants have to do two things to change the rules: (1) Get 10% to sign a petition and (2) get a majority vote. If the prompt tells us that they were voted down, this means that they would have already have gotten the 10% to sign on. That's what A gets at. It strengthens because it eliminates the option that the tenants just didn't get the 10%. Does that make sense?
