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This page shows a recording of a live class. We're working hard to create our standard, concise explanation videos for the questions in this PrepTest. Thank you for your patience!

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This page shows a recording of a live class. We're working hard to create our standard, concise explanation videos for the questions in this PrepTest. Thank you for your patience!

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This page shows a recording of a live class. We're working hard to create our standard, concise explanation videos for the questions in this PrepTest. Thank you for your patience!

Comment on this

This page shows a recording of a live class. We’re working hard to create our standard, concise explanation videos for the questions in this PrepTest. Thank you for your patience!

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This page shows a recording of a live class. We're working hard to create our standard, concise explanation videos for the questions in this PrepTest. Thank you for your patience!

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This page shows a recording of a live class. We're working hard to create our standard, concise explanation videos for the questions in this PrepTest. Thank you for your patience!

Which one of the following most logically completes the argument?

This is a Fill in the Blank Question, with the sub-type Main Conclusion-Most Strongly Supported. We know this because the blank in the stimulus appears in the second half of a sentence where the first half begins with “since.” The “since” indicates that the first half of the sentence is supposed to provide support for the second half.

We start off with a fact about “mass production techniques”:

The introduction of mass production in modern industrial economies allowed the owners of industries to lower prices because they could employ fewer workers, many of whom required little training.

This tells us about a causal chain. Let’s make sure we get the causes and effects straight. Mass production techniques (perhaps like the factory assembly line, or use of machinery to produce things) allowed owners to use fewer workers, many with little training. This led to lower prices.

Lower prices allowed workers to buy goods that they previously would not have been able to afford.

The lower prices let workers buy stuff they wouldn’t have been able to afford. The overall relationship looks like this so far:

mass production techniques –caused→ use fewer-less-trained workers –caused→ lower prices –caused→ workers can buy stuff they wouldn’t have been able to

So far, this sounds like a pretty sweet deal for the workers. Now we get to the last sentence, which begins with the transition word, “But”:

But since jobs for workers with little training are more vulnerable to elimination than those for more highly trained workers, ________.

The first half of this statement tells us that jobs for those with little training are more likely to be eliminated than those for more highly trained workers. A manual laborer’s job is more likely to be eliminated than a nuclear physicist’s, for example. Ah, that’s the catch. There’s benefit (can buy more stuff) but there’s also risk (can lose your job).

The second half is the blank we’re trying to fill. We can tell that the blank should be related to the point that workers with little training are more vulnerable to elimination of their jobs, since that’s the point that appears right after the “since.” Beyond that, I’m not sure we can have any more precise prediction. Let’s head into the answers.

Answer Choice (A) highly trained workers have more purchasing power in modern industrial economies than workers who are less trained

(A) is attractive because it’s probably true. In general, highly trained workers probably do have more purchasing power than less trained workers. But that misses the point entirely. The question stem isn’t asking us to identify a true claim. It’s asking us to identify a claim that is supported by the stimulus. (A) is unsupported. While (A) does compare two groups mentioned in stimulus, it compares them on the wrong quality. From the stimulus, we can infer that the highly trained workers probably have better job security than the less trained workers. But which group has more purchasing power? The stimulus is silent. It would be unreasonable to infer that the highly trained workers have more purchasing power simply because they have better job security. Many other factors influence purchasing power, the most obvious of which is wages, something that the stimulus never mentioned.

Answer Choice (B) the introduction of mass production techniques has decreased benefits for workers as it has increased the profits for owners of industries

Like (A), (B) is trying to bait you based on what you might think is true in real life. We all know the familiar narrative that factories and mass production have helped the greedy business owners, while hurting the little people who are working in the factories. But the stimulus never said anything about loss of “benefits” or increased profits. We do know that many workers have jobs that are vulnerable to elimination, but that doesn’t necessarily mean a loss in benefits. Do they have fewer vacation days? Fewer sick days? Worse health insurance? Worse parental leave? We just don’t know.

And as for profits to business owners, we also don’t know that. They’ve been able to lower prices, but that doesn’t necessarily mean increased profits. Profits are a function of the overall revenue earned by a company minus the costs. Lower prices don’t tell us about revenue or about costs.

Answer Choice (C) even the highest paid employees in modern industrial economies are never able to achieve job security

We don’t know about the group of “highest paid employees.” (C) is trying to get you to think that the workers who are highly trained are highly paid; but the stimulus doesn’t say anything that suggests this. We also can’t say that there’s anyone who is “never able to achieve job security.” Maybe there are certain very highly skilled workers who do have job security? We just don’t know.

Correct Answer Choice (D) a source of increased purchasing power for workers in modern industrial economies also undermines their job security

There’s enough in the stimulus to provide support for (D). This answer is testing whether we can keep track of a causal chain.

Think back to the chain set forth by the stimulus. Mass production techniques were the source of the employer’s ability to hire fewer workers, many with little training. This led to lower prices that allowed workers to buy stuff they couldn’t otherwise buy. So the mass production techniques are a source of “increased purchasing power” for workers – they have the power to buy more stuff. Good for them.

But, those mass production techniques are also something that undermines job security for workers. First, it allows companies to hire fewer workers, which means many existing workers might not be around for long, since companies won’t need as many of them. In addition, mass production techniques also mean that many workers who end up remaining will have little training, which the stimulus tells us leaves those workers more vulnerable to having their jobs eliminated.

Answer Choice (E) the percentage of workers who can afford to purchase goods produced by modern industrial techniques is shrinking

We know that mass production techniques have allowed many workers to buy more stuff. But nothing in the stimulus suggests that the percentage of workers who can buy more stuff is now going down. Sure, many workers might lose their jobs, but we don’t have any reason to think that the number of workers who lose their jobs is more than the number of workers who can now buy stuff that they couldn’t.

In any case, we don’t even know that losing one’s job means you can’t afford the goods – there could be a lot of inexpensive goods that are still affordable. And, on top of that, (E) refers to goods “produced by modern industrial techniques.” The stimulus never mentioned that the goods were produced by the modern industrial techniques. It only said that the goods would be sold for lower prices, which made them purchasable by workers. Whether the lower prices are due to the modern techniques, or whether the lower prices are due to the fact owners didn’t need to hire as many people is something we don’t know.


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This question is a great example of how recognizing the contrapositive argument structure can be helpful. If you spot it in this problem, then you’re more likely to anticipate what we’re looking for in the answer choices.

The question stem says:

Which one of the following most logically completes the argument?

This is a Fill in the Blank question. We can see that it’s a Main Conclusion-Most Strongly Supported type of Fill in the Blank, because the blank appears in a sentence that begins with “Apparently…”. That word suggests that the rest of the statement will be something that follows from the previous line. It’s apparent from the previous lines. So let’s get into the stimulus.

The mu mesons generated by cosmic rays just outside Earth’s atmosphere travel to Earth at speeds approaching the speed of light. Mu mesons generated in the laboratory, however, are nearly at rest.

What in the world is a “mu meson”? Don’t worry, it doesn’t matter. The LSAT is trying to confuse us by using weird scientific terms. Focus instead on the contrast the first two sentences introduce. The mu mesons generated by cosmic rays just outside the Earth’s atmosphere travel very fast to Earth – near the speed of light. The mu mesons generated in the lab are “nearly at rest” – that seems to mean they’re not moving fast. So some mu mesons are super fast, and other ones are very slow.

We do need to keep track of which mu meson is which – but the description associated with each mu meson is too long to keep in our minds easily. It’s OK to condense the description and lose some of the detail, as long as you know that’s what you’re doing. So I’ll say that the mu mesons generated outside the Earth’s atmosphere are fast. The mu mesons in the lab are slow.

Mu mesons generated in the laboratory typically decay in much less time than it takes for a mu meson to travel from just outside Earth’s atmosphere to our detection apparatus on Earth.

This is a comparative statement that we have to unpack. It’s telling us about mu mesons generated in the lab and how fast they decay. What is their decay speed? Faster than it takes for a mu meson to travel from just outside Earth to some detection thing on Earth. Faster than other mu meson’s travel speed.

To help me understand this, I’ll come up with some fake numbers. Let’s say a mu meson in a lab decays in 10 seconds. That means a mu meson traveling from just outside Earth’s atmosphere to the detection thing on Earth takes longer - more than 10 seconds.

I have absolutely no idea where this is going. But let’s press on.

If mu mesons traveling through the atmosphere at speeds approaching the speed of light typically decay as fast as they do in the laboratory, then we should detect only about one one-hundredth of the number we actually do detect.

There’s a lot going on in this sentence. First, it’s a conditional statement. If the first part is true, then the second part is true. Second, it gives us enough to trigger the contrapositive of that statement.

Let’s break it down.

If the outside-atmosphere mu mesons typically decay as fast as they do in the laboratory, then we should detect a much smaller number – say, 10 mu mesons. That’s just a number I’m making up to help me understand this.

But the statement says “we should detect only about one-hundredth of the number we actually do detect.” That bolded part is telling us a fact: we detect more than what we should. So we actually detect 1,000 mu mesons, not 10.

That fact is what triggers the contrapositive. Since we know that we detect far more than 10 mu mesons, that means that the outside-atmosphere mu mesons do not typically decay as fast as the lab mu mesons. If they did decay as fast as the lab ones, then we’d see only 10. But we see a lot more than 10.

At this point, we’ve recognized the contrapositive inference. So we can expect that the conclusion of this argument, which is in the next line, is likely to have something to do with that inference.

Apparently, mu mesons moving at speeds near the speed of light ___________.

What makes sense to say about mu mesons moving at speeds near the speed of light? Remember, those are the mu mesons from outside the Earth’s atmosphere. The sentence immediately before this line allowed us to conclude that those mu mesons do not decay as fast as the lab mu mesons. So this blank should probably be filled by that idea or something close to that idea – these mu mesons do not decay as fast as the lab mu mesons.

Answer Choice (A) take longer to reach Earth than was supposed

Nothing in the stimulus causes us to question how fast the mu mesons really take to reach Earth. We know that they travel to Earth at speeds approaching the speed of light – that’s from the first sentence. No other statement undermines that claim. Although the statement immediately before the last sentence does suggest that we see a lot more mu mesons than we would expect if the outside-atmosphere mu mesons decayed faster, that statement doesn’t imply anything about how fast the outside-atmosphere mu mesons move. It only tells us something about how fast they decay (which means to break down).

Answer Choice (B) are quite difficult to detect with available equipment

The idea of difficulty of detection seems to come out of nowhere. The stimulus does mention the idea of detecting mu mesons with some kind of apparatus. And we do know that we detect a lot more mu mesons than we should if the outside-atmosphere mu mesons decayed more slowly. But what does any of this have to do with difficulty of detection? If you picked this answer, you must be making some kind of assumption connecting something the stimulus to difficulty of detection. Ask yourself what connection you’re making and whether that’s reasonable.

Answer Choice (C) are much less numerous than previously thought

This answer almost sounds like it goes against the stimulus. We know that we are detecting more mu mesons than we should if the outside-atmosphere mu mesons decayed more slowly. So if the stimulus did suggest anything about what our prior expectations were, it would seem that we actually expected to detect far fewer mu mesons. But we actually found more. So it’s wrong to say that mu mesons are “much less numerous than previously thought.” It would make more sense to say that they are more numerous than previously thought.

In any case, we actually don’t have enough in the stimulus to say anything about prior expectations. Notice that the stimulus never suggests anything about what people previously thought or expected. Although we do have a conditional that starts:

If mu mesons traveling through the atmosphere at speeds approaching the speed of light typically decay as fast as they do in the laboratory…

This doesn’t imply that anyone actually used to think that those mu mesons decayed as fast as they do in the lab. We don’t know what anyone expected about the speed of decay. I can say, “If today were the 1980s, we wouldn’t be able to use the Internet.” That doesn’t mean anyone actually thinks that today is in the 1980s.

Correct Answer Choice (D) decay more slowly than mu mesons almost at rest

This is correct, because it matches the contrapositive inference that we can expect from the sentence immediately before the sentence with the blank. Remember, we were looking for the idea that the outside-atmosphere mu mesons do not decay as fast as the lab mu mesons. The beginning of the stimulus told us that the lab mu mesons “are nearly at rest.” This answer is trying to throw us off by using the “nearly at rest” idea instead of saying “lab mu mesons.” But based on the stimulus, the lab mu mesons are the ones that are nearly at rest. So this answer is the same as one that says “decay more slowly than the lab mu mesons.”

Answer Choice (E) are probably not generated by cosmic rays

We have no basis to say that the fast-traveling mu mesons are not created by cosmic rays. The stimulus tells us that mu mesons generated by cosmic rays outside the Earth’s atmosphere travel fast. But whether there are other fast ones that are not generated by cosmic rays is a complete unknown.


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Which one of the following most accurately expresses the conclusion drawn in the columnist’s argument?

This is a Main Conclusion question.

Many people with access to the Internet express a longing for emotional connection to a global human community. This longing often leads them to use the Internet to learn about other cultures.

The stimulus starts off with two sentences providing context – (1) there are a lot of people with access to the Internet who want an emotional connection to people around the world, and (2) this desire often leads those people to use the Internet to learn about other cultures.

Once we hit the word, “However”, that signals where the author’s opinion comes in:

However, learning about other cultures probably will not satisfy their longing…

The author thinks that learning about other cultures probably won’t “satisfy their longing.” That sounds like a conclusion for two reasons. First, it’s a prediction about what will happen, and predictions are often conclusions – you naturally want a prediction to be backed up by evidence. Second, it’s an opinion about the effectiveness of something. When someone tells you that something is good or bad for achieving a certain goal, you’re probably wondering, “Why should I believe that?”

And we can confirm that the author’s opinion is the conclusion here by the word “for,” which follows it and introduces the rest of the stimulus:

…for the Internet is utilized primarily for acquiring information rather than developing feelings of interconnectedness.

“For” is used as a premise indicator here. You can replace “for” with “because,” and the statement will still make sense. Why will learning about other cultures probably not satisfy those people? Because, the Internet is used primarily for getting information rather than developing feelings of interconnectedness.

If you’re especially attuned to flawed reasoning, you might notice that this argument isn’t valid. Just because the Internet isn’t used mainly for the purpose of feeling interconnected does not mean that it can’t help you feel more interconnected. An action can have an effect, regardless of whether its purpose was to produce that effect. I don’t scroll through social media for the purpose of feeling FOMO, but scrolling through social media still has that effect.

In addition, the stimulus is referring to a particular kind of person: people whose longing for interconnectedness leads them to use the Internet. Their kind of Internet use isn’t necessarily the same as the average Internet use. Most of the time, the Internet is used to look up the hours a restaurant is open, or to see the weather forecast, or to get the schedule of a train. Perhaps that usage doesn’t make us feel more connected. But what about reading the Wikipedia page for Japanese culture, or browsing the Brazil subreddit? Perhaps we can feel an emotional connection from that kind of use.

All this discussion of flawed reasoning, however, is beside the point on this question. We’re just looking for the conclusion, and we found it – it’s the line “learning about other cultures probably will not satisfy their longing.” If we flesh out the referential language “their longing,” the full conclusion is “learning about other cultures probably will not satisfy the longing for emotional connection to a global human community that many people feel.”

Answer Choice (A) It is common for people who have access to the Internet to express a longing for emotional connection to an international human community.

This is just a restatement of the first sentence, which is context.

Answer Choice (B) The longing for emotional connection to a global human community frequently leads people to use the Internet in order to acquire information about other cultures.

This is a restatement of the second sentence, which is also context.

Answer Choice (C) People who have access to the Internet tend to use it primarily for acquiring information and only secondarily for developing feelings of interconnectedness.

This isn’t even supported by the stimulus. We don’t know that developing feelings of interconnectedness is the secondary reason people use the Internet. The last part of the stimulus merely said that it wasn’t the primary reason – that doesn’t imply it’s the secondary reason. Maybe it’s the third, fourth, or twentieth reason. Or not a reason at all. In any case, even if this answer were supported by the stimulus, it’s still not correct, because it’s just trying to restate the premise.

Correct Answer Choice (D) For people desiring connection to a global human community, learning about other cultures through the Internet probably will not provide emotional connection to those cultures.

This is what we’re looking for. Although it has different phrasing, it’s expressing the idea that learning about other cultures probably won’t satisfy the longing for emotional connection with a global community that many people feel.

Answer Choice (E) When people long for connection to a global human community, they tend to engage in behavior that results in the acquisition of knowledge about other cultures but rarely produces genuine emotional connection to those cultures.

(E) is tempting because it combines a lot of words the stimulus used, and sounds close to something the author actually thinks. But it’s wrong because it’s about the wrong group of people.

First, this answer states that people who long for connection “tend to engage in behavior that results in acquisition of knowledge…”. But the conclusion is specifically referring to people who engage in a particular behavior – using the Internet to learn about other cultures. It’s not making a statement about people who open up a book, or ask a friend, or do other things to gain knowledge.

Second, the first clause of this answer also refers to the wrong group of people: “When people long for connection to a global human community…”.

The first sentence of the stimulus starts by referring to a particular set of people – people with access to the Internet. It then specifies a subset of those people – those who also express a longing for emotional connection to a global community. The second sentence refers to a subset of that subset – those who also use the Internet to learn about other cultures. The conclusion is about that subset.

(E) makes a statement about the set of people who “long for connection to a global human community.” But this is broader than the set of people who (1) have access to the Internet, (2) have the longing, and (3) use the Internet to learn about other cultures.


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Which one of the following would most logically complete the argument above?

This is a Fill in the Blank Question, with the sub-type Main Conclusion-Most Strongly Supported. We know this because the question stem asks us for what would “most logically complete the argument” above, and the blank in the stimulus follows the language, “We should conclude that use of these pesticides …”

Let’s read the stimulus to see what we’re told about pesticides and their use.

The first sentence begins with what seems to be a potential concession:

Although there are immediate short-term gains in crop yield from a single application of certain hydrocarbon-based pesticides to fields on which they have not been previously used, …

By using “although,” the author of a stimulus commonly introduces a point that she concedes is true, but signals that she will shift direction to focus on something else, or introduce a contrast.

That’s exactly what’s happening here. The author acknowledges that if we use certain pesticides on fields they haven’t been used on before, there are short-term gains in crop yield. This means that we will be able to harvest more crops, at least in the short time after we use the pesticide. That seems like a good thing, right?

Not so fast – we are about to get the contrast:

… studies have shown clearly that long-term use gradually depresses crop yield from this initially elevated level.

Long-term use of the pesticide (as opposed to the first-time use on a field that the pesticide hasn’t been applied to) will decrease crop yield after the initial increase. So long-term use of the pesticide isn’t so great for crop yield.

Notice, however, that it doesn’t say that long-term use of the pesticide brings crop yield down to below where it was before we started to use the pesticide. It only says that it brings crop yield down to below the “elevated level” immediately after the short-term pesticide use.

Thus, we should conclude that use of the pesticides ___________.

What makes sense to put in this blank? Well, since the previous line emphasized the long-term impact of pesticides on crop yield, we can expect the answer to relate to that impact.

Answer Choice (A) is uneconomic

This is a tempting trap answer. Although long-term use of the pesticide decreases crop yield from the higher level that we see immediately after short-term pesticide use, that doesn’t mean use of the pesticide is uneconomic overall. The judgment that something is “uneconomic” involves all sorts of other factors – how much does it cost to use the pesticide? Is the extra short term crop yield worth more than whatever decrease occurs after long term use? What if in the short-term we can sell so many more crops that using the pesticide ends up being economically justifiable? This is why we can’t conclude that use of the pesticides is uneconomic.

Answer Choice (B) damages the environment

Remember, we’re trying to fill in the blank that follows these particular statements in the stimulus. We’re not just trying to pick something that you think is true about pesticides. It doesn’t matter whether it’s reasonable to think that pesticides damage the environment – maybe it is, maybe it isn’t. I’m not going to engage with that question. What matters is that the stimulus didn’t say anything about environmental damage; it mentioned the pesticide’s impact on crop yield. That’s it. So the correct answer should be something that can be tied to the impact on crop yield.

Answer Choice (C) will eventually make pest problems unmanageable

Can you point to any line in the stimulus that suggests the pesticide will make pest problems unmanageable? The stimulus simply spoke about the short term and long term effects of the pesticide on crop yield – the amount of food you get from the crops. So we have no basis to conclude something about pest problems.

If you chose (C), ask yourself why? I have two hypotheses. One is that, similar to (B), you might have simply relied on information you knew from the world. You might have read news stories about overuse of pesticide giving rise to pesticide resistant pests. Sure but that’s not information in the stimulus. My other guess is that you may have been trying to explain why crop yields gradually decrease. You might have hypothesized that it’s because of pesticide resistance. But that hypothesis is far too speculative. Sure, it’s a possible hypothesis but there are way too many possible hypotheses. For example, consider (D).

Answer Choice (D) is probably not occurring in accordance with manufacturers’ instructions.

This too is a possible explanation of the gradual decrease in yields. But just like (C), it’s far too speculative. We don’t know what the manufacturer’s instructions said, nor can we guess about it. Did the farmers follow those (unknown to us) instructions? Who knows? None of the statements in the stimulus refers to instructions or anything that would be evidence of those instructions.

Correct Answer Choice (E) gives financial returns that diminish over time

This is a pretty tough correct answer. The LSAT knows that you’re looking at the phrase “financial return” and thinking that the stimulus didn’t mention that. And they’re hoping that you then pick something like (A) or (B). But what you’re ignoring is that the sentence immediately before the concluding blank was about the short term and long term effects of the pesticide. There’s a spike in crop yield in the short term, but in the long term, the level of crop yield “gradually decreases.” The blank that we’re trying to fill in is a conclusion that follows from that statement.

With that in mind, (E) follows from stimulus’s claim that the level of crop yield “gradually decreases.” Over time, after the initial increase, the crop yield will go down. Will decreased crop yield mean diminished financial return? Yes – why do farmers grow crops? To sell them. In the context of this stimulus, that is a highly reasonable assumption. So if they start to get fewer and fewer crops from the fields on which the pesticides are used, then they’re selling fewer and fewer crops from those fields. This means the return they’re getting from the pesticides is diminishing.


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