## #3 - After purchasing a pot-bellied pig at the pet store in

Administrator
PowerScore Staff

Posts: 6649
Joined: Wed Feb 02, 2011 4:19 pm
Points: 3,321

Complete Question Explanation

Assumption. The correct answer choice is (A)

In this stimulus, the city official makes the following simple argument:

Premise: Springfield city codes classify pigs as livestock.

Premise: Individuals may not keep livestock in Springfield.

Conclusion: Amy would not be allowed to keep the pot-bellied pig as a pet.
The question stem asks us to identify the assumption required by the official's argument. By applying the Assumption Negation technique, we can see which answer choice, when negated, weakens the argument.

Answer choice (A): This is the correct answer choice. If we negate this answer choice, we get the following: "Amy does not live in Springfield." If this is true, the official's argument falls apart, because the city codes where Amy does live might allow keeping livestock.

Answer choice (B): This is not an assumption required by the argument. If we negate this answer choice, we get: "Pigs are classified as pets in Springfield." Even if this were the case, a general prohibition of livestock is broad enough to prohibit all livestock, including livestock animals that are considered pets.

Answer choice (C): This is not an assumption required by the argument. Even if this weren't the case, that would not be problematic to the official's argument. That is, if we negate this answer choice we get "not any non-livestock animal can be kept in Springfield," which has no effect on the argument that Amy can't keep her livestock as a pet in Springfield.

Answer choice (D): This is not an assumption required by the official's argument. If we apply the Assumption negation technique, we get the following" "Dogs and cats are classified as livestock in Springfield." This would broaden the ramifications of the general livestock prohibition, but it would have no effect on the argument that Amy cannot keep her pig as a pet.

Answer choice (E): This is not an assumption required by the argument. Negating this choice: "It is illegal for pet stores to sell pigs in Springfield." This would have no effect on the argument that Amy is prohibited from keeping her new pet.
Blueballoon5%
LSAT Master

Posts: 160
Joined: Mon Jul 13, 2015 1:22 am
Points: 127

Administrator wrote:Answer choice (C): This is not an assumption required by the argument. Even if this weren't the case, that would not be problematic to the official's argument. That is, if we negate this answer choice we get "not any non-livestock animal can be kept in Springfield," which has no effect on the argument that Amy can't keep her livestock as a pet in Springfield.

Hello. I am having trouble with negating sentences. I was wondering if you could help me with this (mostly to confirm my understanding of the explanation). In the answer choice C, the sentence reads: "Any animal not classified as livestock may be kept in Springfield." In this sentence, do we (1) negate the term "any" to "not any", or (2) remove the "not"?

In the explanation from the answer key (quoted above), the administrator seemed to do the first. And with the "not," they just used "non-livestock" to shorten the longer way of saying the same thing, "not classified as livestock." Is this correct? (I am not sure I am reading the explanation correctly).

Additionally, what does this negated sentence mean? I am not sure what a "not any" means. Does this mean that only some or no non-livestock animals can be kept in Springfield, but there is no indication that all non-livestock can be kept?
Adam Tyson
PowerScore Staff

Posts: 2540
Joined: Thu Apr 14, 2011 5:01 pm
Points: 2,354

Take a look at answer C conditionally, blueballoon, and you will see that it is saying IF an animal is not classified as livestock, THEN it can be kept in Springfield. The negation of that claim is something that makes that conditional claim false, by showing that the alleged necessary condition isn't actually necessary. My preference for doing that would look more like "even if an animal is not classified as livestock, it still might not be allowed in Springfield." Our explanation is getting there another way, but is saying the same thing, in that it means that non-livestock animals cannot all be kept in Springfield, but there are some animals that are not classified as livestock that still can't be kept there. In either case, the first condition (not classified as livestock) does not require the second condition (it can for sure be kept there).

When you are stuck on negation, try just this: "It is not true that..." before the answer choice. Here, that would be "It is not true that any animal not classified as livestock may be kept in Springfield." That would have no impact on the argument in the stimulus, because it isn't about animals not classified as livestock, but about one that is.
Adam M. Tyson
PowerScore LSAT, GRE, ACT and SAT Instructor
Follow me on Twitter at https://twitter.com/LSATadam