Here's how I eliminated (D) as unnecessary using formal logic, which I found easier to process.

The stimulus tells us that: in order for the rocket (the whole thing) to be most effective, the engines (its part) must be most effective.

Now imagine that the engines are not being the most effective (negate necessary). This tells us that the rocket cannot be most effective anymore---but it may well still be effective (albeit not most effective)!

Great explanation - the gap in this argument is in drawing a very specific purpose of an activity, when we can imagine other, equally plausible purposes. Essentially, the argument says that "A is done for the purpose of B." B may be the purpose, but maybe not. This plays out twofold.

1. Just because A (lichen fire) can do sth (create smoke), does not mean A was in fact made to create smoke.

2. Even if the fire were started to create smoke, does not mean that the smoke was for meat preservation (this is but one of many equally good purposes).

I think the key assumption in the argument is that minimal improvisation should be the defining feature of jazz---no other feature (or a combination of features) should classify something as jazz. (E) tells us why it might make sense for the later music to count as jazz even with much improv. It gives us a reasonable ground to doubt the prescriptive conclusion.

Right.. if we want to say that the average age changed, it's not enough to say that the number of people changed (we expect that the number changed because the distribution of age groups must've changed). This is why (B) and (D) are wrong: they only mention that the number of people changed (we already have to assume this, as JY said). So the question is how that distribution of age groups shifted. And (A) shows how a distribution of age groups could change in a way that strengthens.

I actually think (B) could weaken, if anything. Wouldn't (B) suggest that the average age is pulled down less strongly (because there is a smaller percentage of age 1s in the region)?

Just wrote mine with RC-LR-LG.

RC - found it a bit tricky, maybe because I got nervous. Topics: big bang, some scholar, some sort of law (I think), and diplomats.

LR - the first half was smooth but the second half was tricky...

LG - had one weird game but was able to finish all questions with maybe 2 guesses.

Another way to label this flaw: rule (principle) v. its consequence (application)

Analogy:

- I might know that the punishment for killing someone in my country is a 5-year jail term

- Person A from a different town (same country) killed Person B

- Doesn't necessarily follow that I now know Person A will go to jail for 5 years (I might not know about the incident)

Two cookie-cutter flaws:

1. Unwarranted generalization

2. Making claims about the future based on the past

(A) exhibits both flaws!

I think (B) is wrong b/c we can't compare the critics' real v. apparent reasons for holding their view. To say that someone has an ulterior motive, we need to show that her purported reason for believing in X is different from her actual reason for believing in X -- we need to compare two conflicting motives for holding a position. But we're not told why the critics themselves believe in their position; we're only told what they think, not why they think what they think.

I think (B) would be correct if the argument went sth like this:

"Most movie critics believe that sentimentality detracts from aesthetic value because (say) it masks other important technical merits of the film. But these critics are wrong because no sentimentality makes movies more interesting for them..."

Simply put, (A) is too general to support our specific hypothesis.

Not only can (A) describe a different phenomenon (as JY shows), even if (A) WERE talking about the same phenomenon as we get in the argument, all that (A) would be doing is to give us the same empirical data from which we derive a particular hypo. That certainly doesn't strengthen the hypo itself -- it leaves our hypo untouched.

One way to strengthen a hypo: provide an example that would be true if our (very specifically tailored) hypo were true. (E) does this because (E) supports what OUR hypo explains (E will most likely be useless if we were to try supporting some alternative hypo for our phenomenon).

In the end, (B) is wrong because not only does it point out a non-problem, but it's also consistent with the argument's conclusion. (B) doesn't attack the underlying (erroneous) assumption that only organic factors (underlying causes) affect manifestations of mental illness.

Potential objections:

1. What if erosion didn't destroy everything that the people possessed?

2. More specifically, what if the 1% of the preserved rubbish is representative of the people's possessions?

3. Or what if the 1% of the preserved rubbish still tells us at least one thing meaningful about what the people possessed?

When I read the argument, 1 was my first thought (which the argument leaves open), and I thought of 2 + 3 as potential objections to the conclusion based on 1.

(B) strengthens by making 1 less likely. If the most durable items are destroyed, it's more likely that nothing is preserved, from which we can gain meaningful insights.

Great explanations of (C) and (D) - thank you!

Just to add: (D) introduces another measure of value -- the "sell price." This weakens because, as JY helpfully explains, there's no reason to think that the "buy price" authoritatively determines/reflects how much one values the gift --- basically: the argument is making an arbitrary assumption. (D) basically calls out this arbitrariness.

Here's how I simplified the argument.

The argument gives us two cases of an ISS (immune system strength) increase: (1) in those who actually laugh (from comics), and (2) in those who tend to laugh more. It then concludes that (2) will see a higher ISS increase.

This presupposes that (1) and (2) represent two separate groups that do not overlap. But it's possible (in fact, likely) that those who tend to laugh more will actually laugh more. That is to say, those in (2) are likely to be in (1)--and therefore--(1) and (2) may not overlap.

Answer Choice (A) calls out this assumption.

We're told 2 things in the argument:

1. A correlation between a group with continued brain damage and a high level of G for its members

2. A causal mechanism (the way in which G can cause brain damage)

... from which we get a causal conclusion.

One problem is that the causal mechanism we're given is conditional, which has to be triggered. The author does not trigger this conditional. AC (D) triggers that conditional, by saying that the fact that we found G = the conditional has been triggered.

Re: Q16, I think it'll be useful to note that para. 3 can also serve as a response to a potential objection (which would say that the alleged women "doctors" were not really midwives). AC (A) will still be correct in this case because blocking a potential objection can work as a premise.

Simplified, this argument is about what should be done based on a narrow consideration (a mere chance to save the product).

When we're concluding that something "should" be done, we're implicitly making an "all-things-considered" judgment (that it's better to do X than not). To weaken this "should" conclusion, we have to introduce some reason AGAINST starting a new marketing campaign.

That's what (D) says.

I think (B) is wrong also because it's actually not describing a flaw--because (B) actually must be true.

By definition, if you're purely motivated by one thing (snobbery), then you're only motivated by that thing. You can't also be motivated by something else in addition (legitimate historical evidence).

Interested!

Here's how I simplified the argument + analysis.

This argument makes a causal conclusion and it tells us two things:

(1) It gives us a particular causal chain.

(2) It says that some drug can lessen the effect in that cause-effect chain.

*The stimulus presents them in reverse order

The difficulty lies in how we strengthen the causal conclusion with fact that some drugs can mitigate brain deterioration (the second component of the argument).

Remember: one way to weaken a causal argument is by showing that without the alleged cause, the alleged effect also disappears. In this argument, the alleged cause = immune cells & the alleged effect = brain deterioration. *Because we're told that the drugs lessens the effect, we need to show that they do so by lessening the alleged cause (immune cells).

That's what (B) shows.

Another way to describe why (B) is wrong:

(D) is simply too broad. The stimulus concerns only a subset of the problems that scientists can solve---it is NOT concerned with ALL problems that scientists can solve. Rather, the stimulus is limited to only those problems that scientists are called upon to solve. Presumably, scientists also work on other research projects on their own initiatives.

Here's my take on why (E) is wrong.

Suppose we negate (E): so Colette did NOT intend to explore important moral questions (IMP) by poetically condensing emotional crises.

According to the argument, Colette's novels are still not indifferent to IMP because it's the fact that Colette discusses emotional crises that makes her novels concerns with (not indifferent to) IMP. The argument is saying that as long as Colette's novels discuss emotional crises, her novels are not indifferent to IMP.

(E) is giving us an additional reason why Colette's novels are not indifferent to IMP (which is her specific purpose behind poetic condensation).

#help

Would it be wrong if I thought that the claim in question is a sub-conclusion/major-premise? I took the last two sentences to be premises that support the claim (because they elaborate on the claim - or give evidence to it).

I still chose (E) thinking major-premise is still a premise (also because (E) was the best answer choice).

Thanks in advance!

(B) is irrelevant because the conclusion isn't about why Thompson will make a good leader -- the notion of good leadership is irrelevant. Being the best person to lead the nation (among other candidates) could still mean that T's leadership is bad absolutely speaking (only relatively better than others). This is possible under the argument and, in this case, (B) would do nothing to the conclusion.

#help

Why can't 'keeping bees' = the presence of bees? This seems just as plausible as 'keeping bees' = 'establishing a beehive'.

Aren't you necessarily keeping bees if you have bees in your garden?

Thank you in advance!

Normal driving conditions =/= same driving conditions.

So spot on