This is a must be true, indicated by: If all of the statements in the above are true, which one of the following statements must also be true?
In the stimulus we are given three sentences that can be converted into conditionals. Reasonable → adapt to the world. Unreasonable → try to adapt world to self. Progress → unreasonable people. The correct answer is going to be something which is guaranteed by these conditionals, their contrapositives, or their combinations. Let’s find it:
Answer Choice (A) Even if the information in the stimulus could guarantee that unreasonable and reasonable people are incompatible in a particular way, such as maybe in how they adapt to the world, it still could not guarantee that they are just flat out incompatible in general.
Correct Answer Choice (B) This answer depends on properly recognizing the contrapositive of “All progress depends on unreasonable people”. Depends means requires, and therefore we can think of this as saying unreasonable people are a requirement of progress. If there are only reasonable people, there are no unreasonable people, and since those are a requirement of progress, then there can be no progress.
Answer Choice (C) This answer makes the classic mistake of confusing sufficiency for necessity. Just because there is no progress without unreasonable people, does not mean there are no unreasonable people without progress. If you selected it, you should review this from the curriculum.
Answer Choice (D) Although we cannot conclude that because all progress requires unreasonable people, all unreasonable people create progress, neither can we conclude that some unreasonable people cannot create progress. All we get from the third sentence is the conditional “if there is progress, then there must be unreasonable people”, and the contrapositive “if there are no unreasonable people, there can be no progress.” What proportion of unreasonable people actually bring about progress is unknown to us.
Answer Choice (E) Just because unreasonable people persist in trying to make the world fit them, doesn’t mean they are more persistent overall than reasonable people. The stimulus tells us nothing about the persistence of reasonable people.
This is a must be true question, because the stem asks: If the statements above are true, then which one of the following must also be true*?*
The stimulus gives us a period of time, the 16 years between 1973 and 1989, and tells us that three things happened during it; total energy use increased less than 10%, specifically electrical energy use grew by more than 50%, and GNP grew by more than 50%. Important things to note are the distinction between the superset general energy use and the subset electrical energy use, as well as the equivalence in percentage growth between electrical energy use and GNP. On to the answers:
Answer Choice (A) The problem with this answer is we know little about overall energy usage. We know the growth of total energy use and of specifically electrical energy use, but we don’t know how the two compare. Let’s say the total energy was 100J, and it increased by less than 10% to 109J. For all we know electrical energy was only 1J and only grew to 2 J. While electrical energy did grow by more than 50%, it still represents an insignificant portion, less than 2%, of total energy use.
Answer Choice (B) This answer wants you to make a similar error as A and assume that electrical energy represents a significant portion of total energy. If this were true, then the much lower growth of energy overall would suggest a decline of non-electrical energy. But we cannot make these assumptions; the correct answer will be certain given the information in the stimulus.
Correct Answer Choice (C) This answer relies on you correctly inferring that if the growth of a whole is lower than the growth of one of its parts, that part grew proportional to the whole. Since we know that total energy use couldn’t have grown more than 10%, and electrical energy use couldn’t have grown less than 50%, the electrical energy use must have grown as a proportion of total energy use. To use our 100J example, 2J is a greater proportion of 109J than 1J is of 100J.
Answer Choice (D) This answer wants you to infer a stronger connection from a mere correlation. We are not entitled to make the assumptions necessary for that inference.
Answer Choice (E) This answer involves non-electrical energy as well as the relationship between GNP and electrical energy use. Because we aren’t given real insight into either of these things in the stimulus, this is a could be false answer.
This is a must be true question, as it asks: If the statements above are true, which one of the following must also be true on the basis of them?
This stimulus is full of conditionals with comparisons. The first sentence and the second half of the second sentence both begin with the conditional indicator “when”, which gives us three conditionals in addition to the “but if” beginning the second sentence. All three conditionals involve comparisons indicated by “than” or “as”. If we notice that the “fall more slowly” of the necessary condition of the first conditional is equivalent to the “fall less rapidly” of the second conditional, and that the “unable to lower prices” of the second conditional is equivalent to the “cannot lower prices” of the third, we should recognize that the three conditionals form a chain: slower adoption → slower falling costs → cannot lower prices → squeezed out. The contrapositive of this chain is: not squeezed out → can lower prices → not slower falling costs → not slower adoption. Since this is a must be true question with a chain of conditionals, we should be looking for answers which say something about a condition earlier in this chain or the contrapositive chain that guarantee a condition further down the chain. Let’s see if any answers take this form:
Answer Choice (A) We are told nothing about raising prices, only stuff about being unable to lower them.
Answer Choice (B) This answer is a classic case of confusing sufficiency for necessity. Just because foreign competitors (FCs) adopting technologies faster is sufficient to squeeze a country out of the global market, doesn’t mean that it is required for a country to be squeezed out of the market.
Answer Choice (C) This answer makes the same mistake as B, just with different parts of our chain of conditionals.
Answer Choice (D) The problem with this answer is that it gives us the negation of the first condition of our conditional chain, because “the same rate” is equivalent to “not slower”, but we can only use the negation in the contrapositive where it is the final necessary condition. Even if A→B is true, we can’t infer anything from B alone. In this case we certainly cannot infer that neither group will be squeezed out of the market. It is entirely consistent with what we are told in the stimulus that there are a million ways a manufacturer can be squeezed out of the market even when it has the same tech adoption rate as its FCs.
Correct Answer Choice (E) Our contrapositive chain comes in handy here. If we look at it, we’ll notice that if a manufacturer can lower prices as rapidly as their foreign competitor, then they must not have slower falling costs, which means that they must not be adopting tech at slower rate. If it is true that a manufacture can lower prices as rapidly as its FCs, then it is required that it is not adopting tech at a slower rate.
This is a strengthen question, and we know that because of the stem: Which one of the following, if true, most strengthens the argument?
Our stimulus tells us that asbestos (which they also include a nice little description of) poses health risks only if it’s disturbed and released into the environment. The author says that since removing it from buildings would disturb it, the government should not require the removal of all asbestos. This argument, as it stands, makes sense. You wouldn’t want to remove asbestos is disturbing it would cause harm. Our instinct is to be alarmed that anyone would support the idea of leaving asbestos in our walls and just living it. This argument assumes that the alternative (removing and putting it somewhere else) is worse.
Answer Choice (A) Plugging this back into the argument does not help the argument. We’re pointing out that asbestos is not as dangerous as all these other things, but that doesn’t strengthen the idea that the government should not require its removal.
Answer Choice (B) This is a conditional statement: if workers do not wear protective gear, asbestos can pose a health threat. What about if they do wear protective gear? Would there still be a threat? We don’t know! In other for this to interact with the stimulus, we would need to know that the workers are not wearing protective gear at the very least.
Answer Choice (C) These relative statements are meaningless: how much more? And is the less dangerous kind of asbestos dangerous in general? At what level? It could be that one is very dangerous, and the other is extremely dangerous. We’ve already said that asbestos, when disturbed, is dangerous - this relative statement does not do anything to strengthen the argument.
Answer Choice (D) This could potentially weaken the stimulus. They’re saying that since the asbestos will eventually get disturbed, what’s the point of preventing its removal now? This answer choice is essentially saying this restriction is unnecessary.
Answer Choice (E) This answer choice draws out a potential alternative proposal for removing asbestos and saying that it’s potentially dangerous: if we require that people remove all asbestos and then put it in a landfill (we can assume a landfill would be where opponents would want to dumb the asbestos), it’s still not safe.
We’ve got a MSS question, which we can tell from the question stem: The statements above most strongly supports the conclusion that comparative advertisements
The stimulus begins with an common opinion of marketing experts about what a company should do in a nonexpanding market. Apparently the best strategy is to go after a bigger share of the market. This makes some sense; if the market as a whole (superset) isn’t expanding, then if an individual company (subset) wants to grow it should try to make up a larger portion of the market. According to these marketing experts, the best way to accomplish this is to run ads comparing your products to rivals and emphasizing their weaknesses. What this first sentence does is gives us a strategy for a specific situation, that of a company in a market that isn’t growing.
The first thing that you should notice in the next sentence is that we are talking about a stagnant market, the food oil market. Something is stagnant if it isn’t changing, so this market is exactly the type of nonexpanding one which the marketing experts strategy applies to. For two years the soybean oil and palm-oil did what marketing experts believe works; for two years they ran advertisements comparing products and emphasizing the bad health effects of each other. Contrary to the marketing experts’ belief, this strategy had little effect on the market shares of either side, and instead many consumers stopped buying edible oil (i.e food oil) at all. Instead of either company (subset) growing, their ads discouraged consumers from buying food oils, strongly suggesting that the food oil market (superset) actually shrunk. Let’s see what strongly supported inference we can make from this information:
Answer Choice (A) Nothing in the stimulus mentions relative superiority between products. We are told about a strategy marketing experts believe in, and then given an example where the strategy didn’t succeed.
Answer Choice (B) The marketing experts advice specifically applied to nonexpanding markets, and our example was of one of these markets. This answer wants you to assume that because a strategy was recommended for specific type of market, it shouldn’t be used outside that market. The problem is that we don’t know anything about how effective comparative advertisements are in those other markets. Maybe even though in this particular nonexpanding market the strategy backfired, it would actually work great in some expanding markets.
Answer Choice (C) This answer choice might be appealing because the one example we are given involved a battle between two companies that led to negative consequences for both sides. The problem is that this answer tries to draw a universal conclusion from a particular instance. Maybe in the car market comparative ads used in retaliation are really effective. We generally want to avoid answers that try to derive an absolute rule from just one example.
Correct Answer Choice (D) D is correct because it avoids the error of C. Where C made a claim that in all cases retaliatory comparative ads are a bad idea, C only says that they might risk a market contraction. It’s important that we recognized the overall decline of the food oil market mentioned in the last sentence of the stimulus, because it tells us that comparative advertising in our example did lead to a contraction of the food oil market. While deriving an absolute rule from a particular case is poor reasoning, a particular case is always good evidence for the mere possibility of a thing. If it rained one day that’s bad evidence that it will rain every day, but good evidence that it can rain.
Answer Choice (E) The example we were given didn’t mention any verification on consumers part. Maybe they did verify the claims about health effects made by both sides and that’s why they stopped buying either product.
We should know this is a weakening question, since it asks us: Which one of the following, if true, most seriously weakens the argument?
This is a 5 star question, and the stimulus throws a lot of stuff to remember at us. The first sentence tells us about a “catch per unit effort” (CPUE) that is used to monitor shark populations in local waters. We are then given a definition of what the CPUE is: it is the number of an individual species of shark that shark-fishing boats catch per hour for each kilometer of net in the water. We’re only two sentences in and we’ve already been given an information overload; South Australia, sharks, catch per unit effort, commercial shark-fishing boats, per hour per km of net. Similar to how low-res summaries are helpful on RC, on dense LR passages it’s helpful to try and translate what’s going on into your own words. Something like “Shark population changes are monitored by how many of a species are caught considering the time and size of net used.”
All of this information so far has just been context on what a CPUE is. Now we are told that there a species of shark whose CPUE has remained constant since 1973. From this the author concludes that the population of the shark species has remained constant since 1973. The major assumption of this argument is that the CPUE of a shark species is an accurate and consistent measure of its actual population changes. While there is always a lot of different ways to weaken an argument, we should expect that this assumption might play a role. An answer that undermines the CPUE’s accuracy and consistency will be a good answer for this question. Let’s see what the answer choices have in store for us:
Answer Choice (A) Always stay anchored in the conclusion. The conclusion we want to weaken specifically specifies that we are interested in the population of the species in the waters around South Australia. Whether or not it is found in other parts of the world is irrelevant.
Answer Choice (B) This might be an appealing answer if your eyes light up at seeing profitable, and you infer that this answer undermines the CPUE because people will only hunt where there are profitable sharks, and maybe the shark species isn’t profitable. The problem is that we don’t know if the species is profitable, and even if it wasn’t profitable we only know that profitable sharks tend to stay in the same spots. Maybe our species isn’t profitable but it is widely dispersed so that it gets caught in the profitable hunting areas. We just don’t have enough information for this answer to weaken the argument.
Answer Choice (C) Interesting! But this answer does nothing to undermine the argument that the CPUE is an accurate indicator of the species real population changes. Even if these nets kill lots of sharks, they still catch them so that we can compare how many are being caught per hour for each kilometer of net.
Answer Choice (D) Again, we just don’t get any information here that can weaken our CPUE is accurate argument. You might want to infer that this would encourage shark-fishers to catch higher numbers of smaller sharks, but that doesn’t affect the CPUE’s accuracy as an indicator of population changes.
Correct Answer Choice (E) What this answer does is give us a reason to believe shark-fishers should be catching a larger portion of shark populations than they did in 1973. If a new device is introduced that should mean higher rates of capture, but the CPUE stays the same, it suggests that the actual population has declined without the CPUE recognizing it. If the population was 20 before but the hunting technology only allowed 1 out of every 10 to be caught, and the population next year declined to 10 but the new device increased the capture rate to 2 out of every 10, the CPUE would stay the same while the population fell by 50%!
This is a Resolve, Reconcile, and Explain Question. We know this because of the question stem, which includes: “...does most to help resolve the discrepancy...” and then gives us exactly what we need to be addressing in the stimulus, which has something to do with predicting the completion of a job. Before we try and understand what that means, we should read the stimulus.
RRE questions will require an explanation of a conflicting set of facts (often 2). Our correct answer choice, when plugged back into the stimulus, will resolve the discrepancy by explaining how the two sides of the apparent conflicting issues actually make sense together. The correct answer will use both sides, though not necessarily explicitly, to explain the conflict. Often, the test will entice you to make naive assumptions about the conflict - don’t fall for it! Your approach should fall under the “this seems wrong because of xyz, but I can think of a few reasons it could work.”
Our first sentence says that officials predicted repaving roads would take municipal road pavers 6 months to complete. They thought it would take a private contractor the same amount of time. However, a private contractor finished in 28 days. Wow - big overestimation by the municipal officials! Now the stem makes a lot more sense.
What could possibly account for this massive difference? A number of things! Perhaps private contractors are able to set their hours and therefore can work at night when roads are less busy, and municipal road pavers are not able to. Maybe the private contractor has a larger crew than the municipality does.
Answer Choice (A) This does not address the predicted vs the actual time it took to complete the project. We need more for this to work. This is out.
Answer Choice (B) This addresses both private contractors and municipal crew. If we were to say that municipal workers can only work 5 days and private contractors set their own hours and can/do work more hours per week than municipals, then this would be great. Alas, it does not. This is out.
Answer Choice (C) This also does not address the difference between the estimated time for completion and the actual time of completion for private contractors.
Answer Choice (D) This actually deepens the issue. If the municipal crew is larger, wouldn’t they work faster? This is out.
Correct Answer Choice (E) This is good - they’re saying municipal workers have a longer process than private contractors and that’s why it takes them longer. The municipal official's estimation of how long it would take the municipal workers could be correct, but assuming the work process is the same for private contractors would inevitably lead them to estimate the wrong amount of time it would take the contractors to finish.
We should recognize this is a most strongly supported question, because the stem asks: Which one of the following is most strongly supported by the information above?
This is a five star question, and getting right is a real test of your ability to recognize the overall issue behind the details and make a key inference. The first sentence is a fairly straight forward conditional, though we should note that it only says that the article can be ruined, not that it will or must be ruined; badly worn needle → article can be ruined. Next we are told that the sewing machine operators in specifically traditional apparel factories monitor their needles and replace those that begin to wear out. We can infer that this practice would prevent at least one potential cause of clothing articles being ruined, but unfortunately we learn sewing operations are becoming increasingly automated, so the operators who monitor needles in traditional factories are being replaced, and it just isn’t efficient to hire people just for monitoring needles. The stimulus ends with a prediction that a new fancy device that detects needle wear is going to become standard equipment of specifically automated apparel factories.
Alright so sewing needles can wear out, and when they do it can ruin the product being sewn. Traditional factories dealt with this problem through human oversight, but since those operators are being replaced in automated factories and it isn’t efficient to hire people who just monitor needles, it seems like there could be a problem. Luckily, it is expected that a new device is going to become standard which uses sound to monitor needle wear, solving the problem. Let’s see what supported inference we get in the answer choices:
Answer Choice (A) This answer is consistent with what we’ve been told, and even might seem to be supported by the prediction of the new device. The problem is that we are only told that the new device is expected to become standard, which means it isn’t certain that it will, while on the other hand we are told that in the traditional factories needles are monitored and replaced. This answer depends on making many assumptions, and is therefore not strongly supported by the information in the stimulus alone.
Answer Choice (B) What we’ve been told actually makes this less likely; human needle monitors aren’t a viable option for an automated factory because it is inefficient to hire people with the sole purpose of monitoring needles.
Answer Choice (C) All we know is that traditional factories don’t use automated equipment instead of human operators for sewing. It is entirely consistent with the stimulus that everything else in traditional apparel factories is automated. This answer requires that we assume a lot about traditional apparel factories that we just don’t know.
Correct Answer Choice (D) This is the correct answer, but it is tricky to pick up on because it relies on making an inference implicit to the stimulus as a whole. The stimulus is all about the problem of needle wear potentially ruining clothing articles, and how humans or devices can be used to monitor needles. If it were true that needle wear occurred at a predictable rate, than it wouldn’t be so important to monitor the needles, since it could be predicted based on the needle’s usage when it would become badly worn. This is a case where maintaining a grasp on the bigger picture of the stimulus is crucial.
Answer Choice (E) This answer is somewhat supported by the fact that it is specifically an acoustic device that can detect needle wear. However, we can’t assume that detection via sound requires that the needles become increasingly loud. What if the noise worn needles make is quieter than good needles? What if it is the same volume but a different kind of noise? This answer wants you to jump on the detail that the devices are acoustic while missing the broader problem and why it supports D.
This is a weakening question, as the stem asks us: Which one of the following, if true, argues most strongly against the explanation reported in the passage?
The first sentence of the stimulus should be ringing the phenomenon bell in your head; the songbird population of England has decreased within recent years. The following sentence gives us the explanation hinted at in the question stem, a hypothesis for why the decrease occurred. This explanation is that the songbird decrease is correlated with the increase in population of one of the songbird’s predators, magpies, who specifically target their young and eggs. This is a classic weakening question format of phenomenon-correlation-causal hypothesis, a correct answer will likely either present an alternate hypothesis or undermines the correlation. Let’s see what we end up with:
Answer Choice (A) The stimulus specifically states that the phenomenon has occurred in recent years, so this is irrelevant.
Answer Choice (B) This answer connects to the fact that magpies target songbird eggs, but you should recognize that it gives us very little information to work with.
Correct Answer Choice (C) This answer does one of the things we predicted, it undermines the correlation between songbird population decreases and magpie population increases which the explanation inferred as a causal relation. If most cases where songbird populations decreased involved no change in the magpie population, then magpie population growth isn’t an appealing explanation for the songbird decrease.
Answer Choice (D) This answer gives us an explanation of why the magpie population has increased, but we are interested in weakening the casual hypothesis that the magpie population increase caused the songbird population decrease.
Answer Choice (E) I’m glad the magpies are getting a well-rounded diet, but even if magpies eat other stuff, the argument can still infer that more magpies means more eaten songbird eggs and babies.
This is a Resolve, Reconcile, and Explain Question. We know this because of the question stem, which includes: “Most helps to resolve the apparent discrepancy?”
RRE questions will require an explanation of a conflicting set of facts. Our correct answer choice, when plugged back into the stimulus, will resolve the discrepancy by explaining how the two sides of the apparent conflicting issues actually make sense together. The correct answer will use both sides, though not necessarily explicitly, to explain the conflict. Often, the test will entice you to make naive assumptions about the conflict - don’t fall for it! Your approach should fall under the “this seems wrong because of xyz, but I can think of a few reasons it could work.”
Our first sentence is pretty long; however, if you break it down by figuring out the subject and then building onto that, that could be helpful. We're told the aquifers themselves don’t have bacteria but water is chlorinated because it could be contaminated due to cross-contamination with old pipes. Then we’re given a specific instance of municipalities getting water from the same aquifer: there are 50 of them, 30 chlorinate their water and 20 do not. The 20 that do not chlorinate their water have lower levels of bacteria in their water when compared with the 30 that do chlorinate their water. This is surprising! Wouldn't chlorinating the water help reduce the bacteria, especially compared to those who do not chlorinate the water?
The discrepancy is when these 50 municipalities are getting water from the same aquifer, how is it that those who chlorinate their water, supposedly killing bacteria, have higher levels of bacteria than those who do not chlorinate their water? This is a legitimate conflict, but there are things that could explain this. For example, what if the pipes for those 30 municipalities are old and gross and that’s why they chlorinate their water? That could potentially explain it.
Let’s look at the answer choices:
Answer Choice (A) How does this help account for the unexpected level of bacteria in chlorine water? It doesn’t! This information isn’t helpful for our issue.
Answer Choice (B) This could be a reason why the 20 did not chlorinate their water; however, does this explains why the 30 that did have higher levels of bacteria? No. This is out.
Answer Choice (C) This adds more information that deepens the conflict - not only did they not add chlorine, but there are also no other chemicals that they added to disinfect their water. If the opposite was stated, it could work. But as is, this is out.
Answer Choice (D) This answer choice notes something about these two groups that were similar, not how they were different. This won't help us resolve any conflict. This isn’t good.
Correct Answer Choice (E) This answer choice says that the pipes for the 20 municipalities are cleaner because their government has strict requirements for them, and therefore they would not need to add chlorine because their pipes are already in good shape compared to those municipalities that have to chlorinate their water.