Preptests 55 Answers and Explanations (By Ivy Global) Section 3 Logical Reasoning

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1 Preptests 55 Answers and Explanations (By ) Section 3 Logical Reasoning 1. Analyzing the Stimulus We re given a conflicting account of the few portrayals of Socrates. The first, from his midforties, was as an atheistic natural sciences philosopher. The others, after his death, were as a religious ethical philosopher. a) The positivity of the accounts doesn t change the discrepancy between them. b) This is the correct answer. If Socrates shifted to a more religious, ethical focus after his forties, then portrayals of him would also have changed to that. c) Other philosophers are out of scope. d) There s no suggestion that one of these accounts is more controversial than the other. e) Other philosophers are out of scope. This is the only answer choice that helps explain why the portrayal of Socrates in his forties was different from those after his death. 2. Analyzing the Stimulus The board member s conclusion is decisive: your work fails to meet the conditions made under the grant. The evidence is certain: the conditions state that the work does not contain any material detrimental to the foundation s reputation, and there is no mention of laudable achievements. The reasoning is implicit and informal: it rests on the assumption that no mention of laudable achievement = detrimental material. - Couldn t the work have been neutral and not contain either laudation or criticism? a) High intellectual value was not one of the conditions mentioned, and so is irrelevant. b) The condition that no detrimental material is included is a necessary condition, but it s never used as a sufficient one. The problem is with whether or not it was actually violated. c) This is the correct answer. It equates no laudable mention with detriment. d) The intent of the recipient is out of the scope of the conditions given. e) This doesn t matter just violating the one condition is enough to fail to meet the conditions. This is the only answer choice that accurately identifies the flaw in reasoning. 3. Analyzing the Stimulus The conclusion of this argument is that people who succeed in breaking cigarette addiction are most likely to be motivated by the immediate concerns of social pressure against smoking than health concerns. The evidence we re given is that breaking a habit is easiest when people are motivated by immediate concerns.

2 Preptests 55 Answers and Explanations (By ) - What s the gap? Well, in order for this to follow, we need to know that health concerns are a long-term issue, and not an immediate one. a) The severity of the health risk is out of scope we need to connect health risk with longterm concerns. b) This is the correct answer: health is not an immediate concern, which is why social pressure trumps it. c) This may be true, but social pressure and health concerns aren t mutually exclusive according to the stimulus. d) The number of attempts is out of scope. Instead, we need to know how they quit. e) It doesn t need to be one or the other; we re just told that social pressure would be more helpful than health concerns. This is the only answer choice that identifies and fills the gap in reasoning. 4. Analyzing the Stimulus Cassie believes that improving the quality of customer service calls for a reduction in client loads. Melvin concedes that reducing client loads would be nice, but isn t feasible it would require recruiting more agents, which is already too difficult. a) This is the correct answer. It solves the problem of finding more agents while still improving customer service. b) This doesn t help the fact that there s an inability to hire more agents. c) This bolsters Cassie s argument but doesn t speak to Melvin s counterargument. d) This would weaken Cassie s argument by suggesting that there is another, easier way, to better customer service. e) This would strengthen Melvin s argument, not strengthen Cassie s. This is the only answer choice that strengthens Cassie s argument while rectifying the issue that Melvin brings up. 5. Analyzing the Stimulus We re given a set of statements about the star-nosed mole. It has a nose that ends in a pair of tentacles, and these tentacles help moles hunt, because they contain receptors that detect the electric fields that other animals produce. a) This is the correct answer. If moles detect and catch worms and insects, and they hunt via their tentacles, then worms and insects must give off the required electric fields. b) Moles rely mainly on their tentacles, but that doesn t mean they don t use their eyesight a little bit. c) We don t know if the moles use a sense of smell at all; we just know that they mostly use their tentacles.

3 Preptests 55 Answers and Explanations (By ) d) Detection of electric fields could have other benefits beyond hunting. e) Whether or not the mole itself produces an electric field is out of scope. This is the answer choice that is most strongly supported (most likely to be true) by the information given. 6. Analyzing the Stimulus The psychologist tells us that there are many cases typified by the following pattern: a child screams until they get what they want, then stops screaming. This continues and the level of misbehaviour increases. a) This is exactly what happens the child screams in order to get what he or she wants. b) This is true. The child screams, the parent acquiesces. c) This happens; the parents reinforce the child s behaviour, perhaps without realizing it. d) This is the correct answer. In this example the child is unintentionally influencing a parent s behaviour in ways coherent with his or her intended goals. e) This also happens. The child gets what he or she wants by doing what the parent doesn t (screaming.) This is the only answer that does not typify the example the psychologist gives. 7. Analyzing the Stimulus The scientist s conclusion is indecisive: it cannot be concluded that R is safe for humans. The evidence is uncertain: R did not cause cancer in lab rats, but many known human carcinogens do not cause cancer in rats (because they require long-term exposure, and rats are short lived.) a) It isn t evidence against the conclusion it s insufficient to prove the opposite of the conclusion. b) This claim is too broad and is not stated in the stimulus (we only talk about chemical R). c) The short-lived quality of rats in evidence for the conclusion, not the conclusion itself. d) It is insufficient to support this. e) This is the correct answer. It is in insufficient to support the opposite of the conclusion (that chemical R is safe.) This is the only answer choice that correctly identifies the role of the statement. 8. Analyzing the Stimulus The manager s conclusion is indecisive: there is no reason to offer free gift wrapping. The evidence is certain: if most customers take it, it will be expensive and time-consuming. If most don t, then there is no advantage to offering it.

4 Preptests 55 Answers and Explanations (By ) - The manager forgets to take into account that there may be equal amounts of people who want it and don t want it. It may be profitable and not too timeconsuming if this is the situation. a) We don t know what happened in previous seasons, nor do we need to for the argument to proceed. b) Slowing down shoppers is not a part of the argument. c) Charging for gift wrapping was not one of the options given in the stimulus. d) We don t know if informing customers is what s expensive, we just know that if a lot of people take the offer it will be expensive. e) This is the correct answer. There s no middle amount option. Since this is a necessary assumption question, we can negate the answer choice, and it will make the argument fall apart. A group other than few or most customers would want free gift wrapping, highlights exactly what the argument misses. 9. Analyzing the Stimulus The conclusion is decisive: behaviour modification is more effective than sleeping pills in helping people fall asleep. The evidence is certain: some people take sleeping pills, and some practice behaviour modification without sleeping pills. Those that practice behaviour modification fall asleep more quickly than those who take sleeping pills. The reasoning is implicit and informal, resting on the assumption that both groups of people had the same level of difficulty falling asleep before they started treatment. - Isn t it possible that the sleeping pills group actually saw the most improvement, and they just started at a worse level? a) Number of hours sleeping is out of scope. This argument is about time it takes to fall asleep. b) People who have no trouble falling asleep are not a part of this study. c) This doesn t do anything to the argument. It doesn t change the fact that the two groups are sleeping pills and behaviour modification, no sleeping pills. d) This is the correct answer. It takes our pre-phrased gap (starting levels of difficulty) and widens it (sleeping pills group was worse off to begin with). e) The preferences of the people who use behaviour modification techniques are out of scope this has no effect on their falling asleep. This is the only answer choice that identifies the gap in reasoning, and widens it, thereby weakening the argument. 10. Analyzing the Stimulus The lawyer s conclusion is indecisive: the witness s testimony should be excluded. The evidence is certain: the witness claimed to recognize the assailant, but not the client, who is a famous TV personality.

5 Preptests 55 Answers and Explanations (By ) The reasoning is implicit and informal: the witness did not recognize both parties, and so the testimony cannot be included. a) This is the opposite of what we want (we re confusing sufficient and necessary conditions here.) The recognition of both parties isn t sufficient for including testimony, it s necessary for it. b) Other witnesses are out of scope and do not change the lawyer s argument. c) This is irrelevant and is certainly not assumed by the argument. d) This is the correct answer. Recognizing both parties is required for the testimony to be included. e) This is out of scope. Both parties need to be recognized; there s no judgment about recognizing the famous client (don t be thrown off by the repeated use of famous TV personality. ) This is the only answer choice that finds the gap in reasoning and identifies the assumption. 11. Analyzing the Stimulus The biologist s conclusion is decisive: the suggestion that the difficulty of adapting to ice ages was responsible for the evolution of the human brain must be rejected. The evidence is certain: most other animal species adapted to the ice ages with no evolutionary changes to their brain. The reasoning is implicit and informal: the biologist reasons that if other species did not present evolutionary changes, then it couldn t be present in this species. a) There is no conditional reasoning in this argument. b) This is the correct answer. It s possible that humans underwent the change even if other species didn t. c) It s not that the condition was needed, but that it was enough to create the change. d) The level of difficulty is out of scope it s the change in brain we re looking at. e) The biologist argues the opposite of this (that there was no causality,) so this can t be her error. This is the only answer choice that accurately identifies the flaw in the biologist s reasoning. 12. Analyzing the Stimulus We re given a set of statements here. Since TV has become available, the total number of book titles published has quadrupled. The retail sale of books increased rapidly during the early days TV and is still increasing today, albeit more slowly, while library circulation has flattened out or begun to decline recently. a) There s no evidence that causation is occurring here. There could be a third factor affecting both books and TV, or it could be coincidence. Beyond this, we don t even know if reading has decreased, since book sales have increased.

6 Preptests 55 Answers and Explanations (By ) b) Again, there s no evidence of causation here. There could be third factor, or it could be a coincidence. c) There s no evidence of this we re told that the increase of new titles has slowed in the past few years, but we may still sell more old copies, or there just may be fewer titles. d) This is the correct answer. Since the number of books sold and published increased, TV didn t necessarily cause fewer to be sold or published. e) We don t know this to be true, since the library market flattened or declined. This is the only answer choice that is most strongly supported (or most likely to be true) by the stimulus. 13. Analyzing the Stimulus The botanist s conclusion is decisive: the belief that poinsettias should be kept outside of homes with pets of children is mistaken. The evidence is certain: research has conclusively shown that the plants do not in fact pose any risk to children or pets. a) This is not stated nor supported by the argument. b) This is a premise. c) This is a premise, which is shown to be false. d) This is the correct answer. e) This is a premise. This is the only answer choice that accurately identifies the botanist s conclusion. 14. Analyzing the Stimulus The conclusion is indecisive: the building being studied was probably not a dwelling. The evidence is certain: most of the buildings from the site were human dwelling composed of only limestone, but this one was composed of quartz, granite, and limestone. - Something is missing from this that would help us reach the conclusion, and the answer choice should tell us this. a) This doesn t change anything we re already told that most of the buildings were made of limestone. b) This is the correct answer. The buildings that were more than just limestone (as this one is) were generally not dwellings. c) This doesn t help us to figure out why quartz and granite would preclude the building from being a dwelling. d) This is already stated in the stimulus. e) Where quartz is found is out of scope; it doesn t help us connect the dots. This is the only answer choice that helps bridge the gap in reasoning, thereby strengthening the argument.

7 Preptests 55 Answers and Explanations (By ) 15. Analyzing the Stimulus Let s diagram this out to understand it best: TR on time accountant prepares + no additional documents (no accountant OR additional documents TR not on time) Accountant additional documents No additional documents Accountant Therefore, TR not on time. It s easy to see that this is valid reasoning, since the two required conditions conflict with one another. a) This doesn t give us the two required conditions that the stimulus does. b) This also doesn t give us the two required conditions that the stimulus does. c) This also doesn t give us the two required conditions that the stimulus does. d) Again, we don t have the two required conditions that the stimulus does. e) This is the correct answer, and matches the reasoning in stimulus. We re given two required conditions, and then told that they conflict with one another, so the desired result isn t possible. This is the only answer choice that matches the stimulus in reasoning and structure. 16. Analyzing the Stimulus Here we`re given a set of statements. The media only report death in commonly threatening scenarios when they happen under an unusual instance, but universally report deaths from rare threats. People estimate risk based on how frequently the threats come to their attention. a) Governmental action is out of scope and is never mentioned in the stimulus. b) The argument is about the frequency of a threat, not the magnitude of it. c) This is the correct answer. People who only engage with news media will see the threats in proportion to their documentation on these. d) What reporters focus on regarding future and immediate threat is out of scope and has nothing to do with the argument. e) The weather is not mentioned and we can t be sure about the frequency of its threats. This is answer choice is most strongly supported (or most likely to be true) by the information given. 17. Analyzing the Stimulus The real estate agent s conclusion is decisive: sellers who are keeping appliances are morally required to either remove them or make it clear that the appliances are not included. The evidence is certain: legally, the sellers can remove impermanent fixtures, but prospective buyers generally assume appliances are included.

8 Preptests 55 Answers and Explanations (By ) The reasoning is implicit and informal: if people would generally assume something to be one way, it is immoral not to make it clear when it will be another. a) This is the correct answer, and connects the gap in reasoning. b) The sellers don t have to stop a person from assuming; they just need to be clear that the assumption is wrong. c) The sellers do not have to include the appliances. They have to make it clear though that they are not including them. d) There s nothing in the stimulus about a deliberate misleading. e) We don t know anything about an indication that appliances are included, just about the implicit assumption. This is the only answer choice that connects the gap in reasoning using a broader principle. 18. Analyzing the Stimulus The author argues that rigorously organizing a child s playtime won t enhance his or her cognitive development and, as evidence, offers an analogy: you can t expect a good novel of an author who is told exactly the plot and characters, so you can t expect to enhance a child s creativity and resourcefulness this way. - Is this a good analogy? Do creativity and resourcefulness = cognitive development? a) We don t have two conflicting goals here. b) A child s enjoyment is not relevant the conclusion is about cognitive development. c) There are no conditions to be mixed up here. d) No conclusions about the author in the analogy are warranted. The conclusion is about the child. e) This is the correct answer, and fits our prephrase exactly. 19. Analyzing the Stimulus The conclusion is decisive: an ideal bureaucracy will have an ever-expanding system of regulations. The evidence is certain bureaucracies attempt to classify all problems, provide an appeal procedure, and expand to cover unanticipated problems if they occur. - For this to connect to the conclusion we need to know that unanticipated problems will occur; otherwise the bureaucracy won t be ever-expanding. a) This actually weakens the argument, by suggesting that the bureaucracy has found all possible problems and therefore doesn t need to continue expanding. b) The complaints don t need to be based on the classification, nor do they need to be on each one they just need to be unanticipated problems. c) This is the correct answer. There always needs to be at least one unanticipated problem for the bureaucracy to continue expanding. d) This is not a biconditional requirement, and the connection happens between the complaints and the expansion, not the primary goal and expansion.

9 Preptests 55 Answers and Explanations (By ) e) Definition and classification are not required for every problem. This is the only answer choice that bridges the gap in reasoning to allow the conclusion to follow. 20. Analyzing the Stimulus Let s look at the structure of this argument: Conclusion: it is unlikely that most types of bacteria hibernate regularly. Evidence: the conclusion that bacteria are usually in hibernation would be reasonable if all type of bacteria were similar, but bacteria are extremely diverse. a) This is a claim that the microbiologists base their conclusion on (which the author refutes.) b) This is the correct answer. c) It s a fact that bacteria are extremely diverse, not a condition. d) This is a claim that the author makes, but it is refuted once we re told that bacteria are extremely diverse. e) This is not stated. This is the only answer choice that accurately states the main conclusion of the argument. 21. Analyzing the Stimulus The conclusion is decisive: if students are given reading but no writing assignments, no students will receive a high grade. The evidence is certain: a student will not complete all the reading assignments if given reading but no writing assignments. The reasoning is implicit and formal: if a student does not finish all the reading assignments, he or she will not receive a high grade (this is the assumption the author makes.) a) This is the correct answer, and connects the gap in reasoning. b) The opposite of this is true (sufficient and necessary conditions have switched): If a student earns a high grade, they must complete all the reading and writing assignments. c) There s no requirement for the students to be highly motivated. d) This is not necessary to the argument, since the conclusion is about not having writing assignments. e) Again, this is not necessary to the argument, since the conclusion is about not having writing assignments. This is the only answer choice that bridges the gap in reasoning. When negated, ( Some students who complete less than all the reading assignments will earn a high grade for the course, ) it invalidates the conclusion. 22. Analyzing the Stimulus The conclusion is decisive: the best way to lose body fat is to eat a lot of protein and avoid carbs.

10 Preptests 55 Answers and Explanations (By ) The evidence is certain: a controlled study showed that those on a high-protein, low-carb diet lost more weight than those on a low-protein, high-carb diet. a) This is the correct answer. This suggests that both groups lost the same amount of body fat, the high-carb group just retained more water. b) The diet still has to be followed it s not enough to just eat a bunch of protein. c) Muscle gain may be a positive, but it s out of the scope of this argument, which is just about body fat loss. d) This weakens, since it gives another reason that the high-carb group should have lost more weight. e) Since they returned to their normal diets, the regain is irrelevant they are no longer on the diet. This is the only answer choice that weakens the argument by undermining the results of the study. 23. Analyzing the Stimulus The essayist makes a strange argument. Computers and the human mind share a common ability (the ability to represent and perform logical transformations on pieces of information), so the human mind is a type of computer. a) This argument makes a conclusion about a common basis of two different things, not about a common ability equating the two. b) This argument is valid since two crafts both follow the same principle, that principle is not distinctive. c) This is the correct answer. Both communities and organisms have the same quality, so they are the same. d) This argument is valid. Selenium is required for vitamin E, so if you don t have selenium, vitamin E won t work properly. e) We re not equating two things here. We re comparing them. This is the only answer choice that matches the stimulus both in reasoning and structure. 24. Analyzing the Stimulus The conclusion is decisive: the objective evaluation of poetry is only possible if the belief that a poem has whatever meaning is assigned to it by the reader is false. The evidence is certain: the aesthetic value of a poem can t be discussed unless at least two readers can agree on an interpretation The reasoning is implicit and informal, resting on the assumption that objective evaluation is only possible if the aesthetic value can be discussed. a) This is stated, and so is not an assumption. b) This needs to allow for aesthetic value, not ensure objective evaluation.

11 Preptests 55 Answers and Explanations (By ) c) It s just the discussion of aesthetic value that isn t possible, not discussion in general. d) This is the correct answer. e) This is required, not the best way. This is the only answer choice that identifies the gap in reasoning and bridges it. 25. Analyzing the Stimulus The dean s argument conclusion is decisive: the demand that the math department teach the statistics course is unjustified. The evidence is certain: a course having math in it does not require that it be taught by a math professor, and this course has no more than high school algebra in it. a) There s no suggestion that the math professors would do a bad job; it s just that they don t need to do the job. b) This is the correct answer. The reason for teaching in the math department is wrong, so the whole view is wrong. c) This is completely irrelevant and the dean never presumes this. d) This is not required by the dean s argument. e) This presumption isn t made; it s simply an analogy given. This is the only answer choice that accurately identifies the flaw in reasoning.