The question stem reads: Which one of the following, if true, most weakens the detective's argument? This is a Weaken question.
The author begins by stating that laser-printed drums can be easily damaged, and a damaged drum will produce a blemish of similar dimension on the documents it prints. The author concludes that if we can match a blemish on the page to a nick on the drum, we can reliably trace suspicious laser-printed documents to the printer on which they were printed. In this question, it is difficult to anticipate where the correct AC will go because this argument does not seem to have a fatal flaw. However, we should be aware of some important elements of the stimulus. First, the conclusion uses the modifier "suspicious," so we are not concerned with any documents, just the suspicious ones. Second, the conclusion does not say we can trace any suspicious document to its printer, just the documents where we can match the blemish to a nick on the drum. Let's proceed to the answer choices and use POE.
Answer Choice (A) is irrelevant to the argument. The argument concludes that we can trace a document to the printer on which it was produced. The argument is unconcerned with who printed the document. If you picked this argument, you likely assumed that the argument's author, a detective, was interested in catching criminals. Perhaps the detective is, but his argument is not. It can be helpful to think of arguments as standing on their own. It does not matter who is making the argument; stick to strictly the premises and conclusions of the argument.
Answer Choice (B) is also irrelevant. The fact that nicks are usually small and require skill to determine size does not imply that we cannot match the blemish to the nick on the drum. Even if it did make it impossible to match the small blemish to the nick, the argument would not be concerned with those documents. Remember, the argument is only concerned with the blemishes we can match.
Correct Answer Choice (C) hurts the argument severely. Let's say the manufacturing process often produces the same nick in three multiple drums. Matching the blemish on a document to that nick would only narrow it down to three printers. That would directly contradict the argument's conclusion, which says we could find the exact printer the document was printed.
Answer Choice (D) is similar to (B). Just because the blemishes are sometimes totally concealed does not necessarily mean we would be unable to find the blemish and match it to the nick. If it were impossible to match a concealed blemish to the drum, then (D) would be irrelevant to the argument. Remember, the arguments are only concerned with documents we are able to match to a drum.
Answer Choice (E) is irrelevant to the argument. The conclusion is concerned only with laser-printed suspicious documents.
The question stem reads: The Conclusion follows logically if which one of the following is assumed? This is a Sufficient Assumption question.
Love is complicated in the real world, which is no different than love in the LSAT. It's possible to love someone and not be loved back. Unfortunately, love is not a biconditional. My previous relationships confirm that. While reading this stimulus, it is essential to see which "way" the love is going. Are you loving or being loved? The stimulus is short and conditional heavy, so let's break these down as we go. The stimulus starts with "whoever is kind is loved by somebody or another." This translates into the lawgic:
kind -> loved by someone
Next, the stimulus claims that "whoever loves anyone is happy." This translated into the lawgic:
Love anyone -> happy
The argument concludes, "Whoever is kind is happy." Translated:
Kind -> happy
Let's organize this argument into:
P1: Kind -> loved by someone
P2: Love anyone -> happy
______________________________________________
C: Kind -> happy
We can kick up the sufficient condition so we now have:
P3: Kind
P1: Kind -> loved by someone
P2: Love anyone -> happy
______________________________________________
C: Happy
We want to get to "happy," and P2 will get us there if we can satisfy "love anyone." Let's make that our necessary condition: (__) -> love anyone. Now we need to find a sufficient condition that will be satisfied by the argument. Notice how P3 satisfies the sufficient condition of P1, so we can infer that "loved by someone" occurs. Let's make "loved by someone" the sufficient condition of conditional: loved by someone -> love anyone. Now we have a valid argument:
P3: Kind
P1: Kind -> loved by someone
SA: Loved by someone -> love anyone
P2: Love anyone -> happy
______________________________________________
C: Happy
P3 will trigger P1, P1 triggers our SA, and our SA will trigger P2, which brings us to the desired conclusion of "happy." Happy is exactly what we are because we just solved this four-star problem. Let's move to the answer choices.
Answer Choice (A) is incorrect. If you picked (A), you likely misread P1 and thought that being kind meant you loved someone. You can rule out (A) quickly by seeing we are missing the concept of "loved by."
Answer Choice (B) is also out. You can rule out (B) because we are missing the concept of "loved by."
Answer Choice (C) is also out. We want to get to "happy," but (C) has "happy" in sufficient condition; we can rule (C) out.
Correct Answer Choice (D) is the contrapositive of our prephase. (D) translate to:
Loves no one -> loved by no one
We take the contrapositive:
/(loved by no one) -> /(loves no one)
Not being loved by no one means you are loved by someone. Not loving no one means you love someone. So we get our SA: "Loved by someone -> love anyone."
Answer Choice (E) is the most popular wrong answer. If you picked (E), you likely thought that (E) would let you infer "loves everyone." "Loves everyone" would satisfy "loves anyone" and deliver you to "happy." The problem with (E) is that it has "Kind" in the necessary. Remember, satisfying the necessary condition has no effect on the sufficient condition.
The question stem reads: The reasoning in the argument is most vulnerable to criticism on which one of the following grounds? This is a Flaw question.
The author begins by claiming that it is clear that Egyptians were the first society to produce alcoholic beverages. That sounds like a conclusion; let's see the author's evidence for that claim. The author then describes how it had been thought the Babylonians were first because they had a process for fermentation around 1500 BC. However, archaeologists have found an Egyptian cup from 2000 B.C. With chemical residue that indicates it contained an alcoholic form of beer. So the author's argument uses the premise that the Egyptian cup is the oldest evidence of alcohol to conclude that Egypt must have been the first society to produce alcohol. Immediately, we can see the author's line of reasoning as flawed. Let's go back in time to 5 seconds before the archaeologists found this Egyptian cup. Then, the oldest evidence we had of alcohol was from the Babylonians. Using the authors' line of reasoning, we conclude that the Babylonians were the first society to produce alcohol. We would be subsequently proven wrong when the archeologists find the Egyptian cup 5 seconds later. All that was needed to prove our argument wrong was finding new evidence that an older civilization had alcohol. Let's return to the present, where the author claims that Egyptians must have been the oldest society to produce alcohol. How do we know we won't find even earlier evidence of alcohol in the future? We can't. The author has made an error in assuming what is true of the past must be true in the future. This is the Problem of Induction.
However, there is an even more fundamental problem. What we humans know has no bearing on the actual truth of the matter. Even if we could see into the future and determine that this Egyptian cup would be the oldest evidence we find, we could not say that Egyptians were, in fact, the first society to produce alcohol. An earlier society could have created alcohol but left no evidence behind for us to find. The upshot is that a lack of evidence for a claim does not constitute evidence that the claim is false.
Answer Choice (A) is incorrect because the claim that Egypt was the first society to produce alcohol is not a generalization about Egyptian society. Either they were the first to produce alcohol, or they were not. A generalization would be that all Egyptians drank alcohol. If the author argued that all Egyptians drank alcohol because we found a single cup in a pharaoh's tomb, then (A) would look better.
Answer Choice (B) is wrong. The premises talk about two distinct types of alcoholic beverage (Egyptian beer vs. Babylonian wine). However, the conclusion talks about alcoholic beverages in general. Alcoholic beer counts as an alcoholic beverage.(B) would look better if the author used the old cup of Egyptian beer to conclude Egyptians were the first society to produce wine.
Answer Choice (C) is incorrect. If we mapped the stimulus onto (C), we would get the following: Because Egpyt developed fermentation before the Babylonians, the development of fermentation in Babylon depended on the development of fermentation in Egypt. Wildly off base from the argument, eliminate.
Correct Answer Choice (D) is what we prephased. The argument does ignore that the first known instance of alcohol (the Egyptian wine cup) is not the first instance of alcohol.
Answer Choice (E) is incorrect. While it is true that the author provides no evidence for the claim that they produced wine as early as 1500 BC, it is irrelevant. If it is true the Babylonians had wine as early as 1500 BC, the Egyptian cup is still older. If it is false, the Babylonians had wine as early as 1500 BC, and the Egyptian cup is still the oldest. Additionally, Even if the author provided evidence for the claim about Babylonian wine, we would still the argument would still be flawed due to the problem discussed in (D).