Test: Logical Flaw - GMAT MCQ

(A) The reasoning in option (A) is flawed because it makes a sweeping generalization based on a correlation. While it may be true that students who attend universities tend to be more successful in life, it does not necessarily mean that all students should attend a university to be successful and avoid failure. Success and failure can be influenced by various factors such as individual skills, interests, and career goals. Therefore, the reasoning fails to consider the diversity of paths to success and oversimplifies the relationship between attending a university and achieving success.

(B) The flawed reasoning in option (B) is based on a false cause-and-effect relationship. It assumes that walking in the rain with an uncovered head directly leads to developing a cold. However, catching a cold is caused by viral infections, not by exposure to rain. While being wet and cold may lower the body's resistance to infections, it does not guarantee that an individual will develop a cold. The reasoning overlooks other factors such as personal susceptibility to infections, overall health, and exposure to viruses.

(C) The reasoning in option (C) is more reasonable compared to the previous options. It suggests that over time, ovens develop a buildup of food residue that gets burned into the bottom, and therefore, ovens should be cleaned annually. This reasoning acknowledges the cause-and-effect relationship between the buildup of food residue and the need for cleaning. However, it does not provide any evidence or specific guidelines for why cleaning should be done annually. The reasoning could be improved by considering factors such as usage frequency, cooking habits, and the severity of residue buildup.

(D) The reasoning in option (D) is relatively sound. It states that "green" products lessen the toxic impact on the environment and implies that purchasing them helps the environment. This reasoning is based on the assumption that reducing toxic impact is beneficial for the environment, which is generally supported by environmental science. However, the reasoning could be further strengthened by providing specific examples or evidence of how green products achieve this goal, and by considering other environmental factors beyond toxicity.

(E) The reasoning in option (E) is flawed because it assumes a direct causal relationship between Stan's temper and his removal from the team. While Stan's temper may indeed contribute to his unpopularity among team members, it does not guarantee that he will be removed from the team. The reasoning oversimplifies the decision-making process and ignores the possibility of alternative resolutions, such as conflict resolution strategies or addressing Stan's behavior. It is important to consider multiple factors and potential solutions when evaluating interpersonal dynamics within a team.

(A) The reasoning in option (A) contains a logical fallacy known as affirming the consequent. It assumes that if leaving the car in the driveway leads to rust, then Edward's car must not be parked in the garage because it is rusty. However, there could be other reasons for the car's rust, and the argument overlooks the possibility that the car was parked in the garage and still became rusty due to other factors such as moisture or poor maintenance.

(B) The reasoning in option (B) employs a logical fallacy known as appeal to fear or scare tactics. It suggests that if you do not purchase the new hand lotion, you will always regret having dry skin. This argument relies on creating fear or anxiety about potential negative outcomes without providing any evidence or logical reasoning to support the claim. It attempts to manipulate emotions rather than providing sound reasoning.

(C) The reasoning in option (C) involves a logical fallacy known as non sequitur or irrelevant conclusion. It states that you cannot purchase a certain SUV because the owner of the only SUV dealership in town has not expressed his opinion on using animals for medical research. The argument tries to connect the owner's beliefs about animal research to the suitability of purchasing an SUV, which is unrelated. The beliefs of the dealership owner have no bearing on the vehicle's quality, features, or suitability for the buyer's needs.

(D) The reasoning in option (D) includes a logical fallacy known as a false dilemma or either/or fallacy. It asserts that if you do not enroll your child in an advanced preschool, they might fall behind other students in elementary school, and therefore, it is essential to enroll them in an advanced preschool. This argument presents a limited set of options (enroll in advanced preschool or risk falling behind) and overlooks other potential factors that can contribute to a child's development and academic success, such as parental involvement, teaching methods, and individual learning abilities.

(E) The reasoning in option (E) resembles a hasty generalization or overgeneralization fallacy. It concludes that because 80% of voters in the western district dislike a proposed legislation, it must be a poor piece of legislation that will offer no benefits to anyone in the state. This argument jumps to a sweeping conclusion based on the opinion of a specific group without considering other districts, alternative perspectives, or potential benefits the legislation may provide. It oversimplifies the situation and neglects the diversity of viewpoints and potential consequences beyond the western district.

(A) This option correctly identifies the flaw in the reasoning. It points out that the relationship between being a criminal and being a rabbit is not of the same kind as the relationship between being suspected and being gray. The analogy drawn in the reasoning fails to consider the different nature of the relationships being compared, leading to an invalid conclusion.

(B) This option states that the relationship between being suspected and being a rabbit is not of the same kind as the relationship between being gray and being a criminal. While this statement may be true, it does not directly address the flaw in the reasoning presented. The key flaw lies in comparing the relationship between being a gray rabbit and being a rabbit to the relationship between being a suspected criminal and being a criminal, not in comparing being suspected to being a rabbit.

(C) This option correctly highlights the flaw in the reasoning. It states that the relationship between being a gray rabbit and being a rabbit is not of the same kind as the relationship between being a suspected criminal and being a criminal. The reasoning incorrectly assumes that because all gray rabbits are rabbits, all suspected criminals must also be criminals, failing to consider the differences between the relationships being compared.

(D) This option, although true, does not address the flaw in the reasoning. It points out that not all rabbits are gray, which is a valid statement. However, the flaw in the reasoning lies in the faulty analogy and the mismatched relationships being compared, not in the color of rabbits.

(E) This option also does not directly address the flaw in the reasoning. It states that not all criminals are suspected, which is a valid point. However, the flaw lies in the flawed analogy and the incorrect assumption that being suspected is equivalent to being a criminal, rather than in the percentage of criminals who are suspected.

In summary, option (C) is the most accurate and directly addresses the flaw in the reasoning by pointing out the mismatched relationships being compared.

(A) The reasoning in option (A) contains a logical error known as the fallacy of affirming the consequent. It assumes that if the murderer left their fingerprints on the knife, anyone whose fingerprints do not match those on the knife can be eliminated as a suspect. However, this reasoning overlooks the possibility of the murderer wearing gloves or the presence of other evidence that could implicate individuals whose fingerprints do not match.

(B) The logical error in option (B) is a non sequitur or irrelevant conclusion. It acknowledges the premise that hard work is necessary for success but concludes that Smith, who was governor, could have succeeded without working hard. The conclusion does not logically follow from the premise and introduces an unrelated assertion about Smith's success.

(C) The reasoning in option (C) involves a logical error known as a hasty generalization or overgeneralization. It assumes that because the person did not break out in hives after eating the pie, it could not have been real pecan pie. This conclusion jumps to a hasty generalization based on a single personal experience and does not consider other possible factors that could explain the absence of an allergic reaction.

(D) The logical error in option (D) is a false dilemma or either/or fallacy. It states that if the inventory cannot be sold quickly, the business will go under. This reasoning presents a limited set of options (quick sale or business failure) and overlooks the possibility of other strategies, such as reducing costs or seeking alternative financing, that could help save the business.

(E) The reasoning in option (E) involves a logical error known as a non sequitur or irrelevant conclusion. It states that only the brave deserve the spoils and concludes that Major Wilson, who has been brave, surely deserves the spoils. However, the conclusion does not logically follow from the premise, as bravery alone does not necessarily guarantee deserving spoils or rewards.

In summary, the reasoning errors in these options include affirming the consequent, non sequitur, hasty generalization, false dilemma, and irrelevant conclusion.

(A) fails to draw the conclusion that the play will not both be adapted as a movie and be revived at the Decade Festival, rather than that it will do neither.

This option suggests that the argument fails to consider the possibility that the play could be both adapted as a movie and revived at the Decade Festival. However, this is not the flaw in the argument. The flaw lies in assuming that because the play is not successful, it will not be either adapted as a movie or revived at the Decade Festival. So, this option is incorrect.

(B) fails to explain in exactly what way the play is unsuccessful.

This option suggests that the argument does not provide a clear explanation of how the play is unsuccessful. While this may be a valid criticism, it is not the main flaw in the argument. The main flaw is the assumption that lack of success automatically excludes the possibility of adaptation or revival. Therefore, this option is not the correct choice.

(C) equates the play's aesthetic worth with its commercial success.

This option suggests that the argument assumes that the play's commercial success is directly related to its aesthetic worth. However, the argument does not explicitly make this equation. It is focused on the play's success in terms of adaptation and revival, rather than aesthetic worth. Hence, this option is not the correct choice.

(D) presumes, without providing justification, that there are no further avenues for the play other than adaptation as a movie or revival at the Decade Festival.

This option points out that the argument assumes that there are no other possibilities or avenues for the play's success besides adaptation as a movie or revival at the Decade Festival. However, the argument does not provide any justification or reasoning for this assumption. This lack of justification is indeed a flaw in the argument. Therefore, this option is a valid choice.

(E) fails to recognize that the play's not satisfying one sufficient condition does not preclude its satisfying a different sufficient condition for adaptation as a movie or revival at the Decade Festival.

This option correctly identifies the flaw in the argument. The argument assumes that because the play is not successful, it will not meet the conditions for adaptation as a movie or revival at the Decade Festival. However, it fails to consider that the play might satisfy different conditions or criteria for these opportunities. Thus, this option is the correct choice.

In conclusion, the correct answer is (E) fails to recognize that the play's not satisfying one sufficient condition does not preclude its satisfying a different sufficient condition for adaptation as a movie or revival at the Decade Festival.

(A) fails to consider the percentage of plays written during Flavius's administration that were not explicitly about Flavius.

This option suggests that the historian overlooks the possibility that a significant portion of the plays written during Flavius's administration may not have been about Flavius himself. While this might be a valid criticism in terms of the scope of the plays, it does not directly challenge the argument's conclusion about Flavius's unpopularity. Therefore, this option is not the most appropriate criticism.

(B) treats the satirical plays as a reliable indicator of Flavius's popularity despite potential bias on the part of the playwrights.

This option suggests that the argument relies on the assumption that the satirical plays accurately reflect Flavius's popularity, without considering potential bias from the playwrights. If the playwrights had personal or political motivations for satirizing Flavius, it could impact the reliability of the plays as an indicator of his popularity. This is a valid criticism and directly challenges the argument's conclusion, making it the correct choice.

(C) presumes, without providing evidence, that Flavius was unfavorably disposed toward the arts.

This option points out that the argument assumes Flavius was against the arts without providing any evidence to support this claim. While this assumption might weaken the argument's conclusion, it does not directly criticize the reasoning used in the argument. Therefore, this option is not the most appropriate criticism.

(D) takes for granted that Flavius's attempt to discourage the arts was successful.

This option suggests that the argument assumes Flavius's attempt to discourage the arts was successful without providing any evidence or justification for this assumption. While it raises a valid point about the lack of evidence, it does not directly challenge the argument's conclusion about Flavius's unpopularity. Thus, this option is not the most appropriate criticism.

(E) fails to consider whether manual labor and moral temperance were widely regarded as virtues in ancient Rome.

This option points out that the argument overlooks the consideration of whether manual labor and moral temperance were widely regarded as virtues in ancient Rome. If these virtues were highly valued, it could undermine the argument's assumption that Flavius's belief in these virtues made him unpopular. This is a valid criticism that challenges the reasoning used in the argument. However, it does not directly address the conclusion about Flavius's unpopularity, making it a less appropriate choice.

In conclusion, the most appropriate criticism of the historian's argument is (B) treats the satirical plays as a reliable indicator of Flavius's popularity despite potential bias on the part of the playwrights.

A. Weight is only one of the health indicators of newborn cattle.

This option points out that weight is just one of the health indicators for newborn cattle and does not directly address the flaw in the reasoning. The flaw lies in equating the current weight of a one-month-old calf with the average weight of Holstein heifer calves in New Zealand. So, this option is incorrect.

B. Some three-month-old Holstein heifer calves weigh as much as 100 pounds.

This option provides information about the weight of three-month-old calves. However, it does not address the flaw in the reasoning, which is based on the average weight of one-month-old calves. Therefore, this option is incorrect.

C. It is possible for a normal Holstein heifer calf to weigh 78 pounds at birth.

This option suggests that a normal Holstein heifer calf could weigh 78 pounds at birth. However, the argument is specifically focused on the weight of a one-month-old calf. This option does not directly challenge the flaw in the reasoning. Hence, it is incorrect.

D. The phrase "below average" in this context need not necessarily mean inadequate.

This option points out that the phrase "below average" does not necessarily mean inadequate. While this is a valid point, it does not directly address the flaw in the reasoning, which is the confusion between average weight and average weight gain. Thus, this option is not the correct choice.

E. Average weight and average weight gain are different metrics.

This option accurately identifies the flaw in the reasoning. It highlights that average weight and average weight gain are different metrics, and one cannot be directly equated to the other. The argument assumes that if the current weight is below the average weight, then the weight gain must also be below average. This option directly challenges that flawed assumption, making it the correct choice.

In conclusion, the correct answer is (E) Average weight and average weight gain are different metrics.

(A) Relies on the truth of a claim by a source that is likely to be biased: This option suggests that the argument's flawed reasoning lies in relying on a biased source for the claims about the health benefits of chocolate and olive oil. However, the argument does not mention any specific biased sources. The focus of the argument is on the flawed reasoning itself, rather than the credibility of the sources.

(B) Applies a general rule to specific cases to which it does not pertain: This option suggests that the argument applies a general rule (the idea that waiting long enough will make any food appear healthful) to specific cases (chocolate and olive oil) where it may not be relevant. While the argument does make a generalization, the flaw is not specifically about misapplying a general rule to specific cases.

(C) Bases an overly broad generalization on just a few instances: This option correctly identifies the flaw in the argument. The argument makes a sweeping generalization about almost any food based on only two instances (chocolate and olive oil). It fails to consider the wide range of foods and the varying results of nutritional research, leading to an overly broad and unsupported conclusion.

(D) Takes for granted that all results of nutritional research are eventually reported: This option points out that the argument assumes that all results of nutritional research will eventually be reported. However, the argument does not explicitly make this assumption. It focuses more on the pattern of changing perceptions of food rather than the reporting of nutritional research.

(E) Fails to consider that there are many foods that are reported to be unhealthful: This option suggests that the argument overlooks the possibility that there are many foods reported to be unhealthful, which contradicts the idea that almost any food will be reported as healthful over time. While this may be a valid consideration, it is not the main flaw in the argument. The primary flaw lies in making an overly broad generalization based on just a few instances, as mentioned in option (C).

(A) Overlooks the fact that something can have the reputation for being of poor quality without being of poor quality: This option suggests that the argument fails to consider that the department may have had a poor reputation even before Professor Smythe became the head. However, this is not the main flaw in the argument. The primary flaw lies in assuming a causal relationship between Professor Smythe's actions and the negative changes in the department, as mentioned in option (C).

(B) Bases a general claim on a few exceptional instances: This option suggests that the argument makes a general claim about Professor Smythe's appointment undermining the department based on a few exceptional instances, such as the resignation of a distinguished faculty member and a decline in certain aspects. However, this is not the main flaw in the argument. The main flaw is assuming a causal link without sufficient evidence, as mentioned in option (C).

(C) Assumes that because an action was followed by a change, the action was undertaken to bring about that change: This option correctly identifies the flaw in the argument. The argument assumes that the negative changes observed in the department (resignation, fewer courses, student dropouts, declining reputation) were directly caused by Professor Smythe's actions as head of the department. It assumes a causal relationship without providing sufficient evidence or considering alternative explanations.

(D) Fails to distinguish between a decline in quantity and a decline in quality: This option suggests that the argument overlooks the distinction between a decline in the quantity of certain aspects (such as courses and students) and a decline in the quality of the department. However, the argument does not specifically make claims about the decline in quality. The primary flaw lies in assuming causation without adequate evidence, as mentioned in option (C).

(E) Presupposes what it purports to establish: This option suggests that the argument assumes what it is trying to prove, namely, that Professor Smythe was appointed to undermine the department. However, the argument does not explicitly state this assumption. The main flaw lies in assuming a causal relationship without sufficient evidence, as mentioned in option (C).

(A) It would prevent the development of safe technologies for producing electric power.

Option (A) suggests that the proposal would hinder the development of safe technologies for generating electricity. Nuclear power is one of the sources of electricity production, and while it has its challenges, it also has the potential for safe and efficient energy generation. By completely shutting down nuclear plants and not exploring alternative safe technologies, the proposal may limit the progress in finding better and safer methods of generating power. Therefore, this option highlights a potential drawback of the proposal.

(B) It does not distinguish between nuclear plants that have, and plants that do not have, a reputation for operating safely.

This option suggests that the proposal fails to consider the varying safety records of different nuclear plants. Not all nuclear plants are equal in terms of safety measures, operational standards, and regulatory compliance. Some plants may have a reputation for operating safely and efficiently, while others may have had incidents or safety concerns. The proposal's blanket approach of shutting down all nuclear plants without distinguishing between their safety records may overlook the possibility of continuing operations at well-managed and secure plants, which could be a more viable solution. Thus, this option raises a valid concern about the proposal's lack of differentiation.

(C) It does not provide for the permanent storage of already-existing waste.

As discussed earlier, this option highlights a significant shortcoming of the proposal. It fails to address the issue of permanent storage for the already-existing radioactive waste from nuclear plants. While the proposal suggests halting the operation of nuclear plants and preventing new ones from being built, it does not present a plan for the long-term disposal of the accumulated waste. Ignoring the existing waste could lead to environmental and safety risks. Therefore, this option correctly identifies a crucial aspect overlooked by the proposal.

(D) The generation of electric power from fossil fuels is relatively safe.

Option (D) suggests that the proposal assumes the safety of generating electricity from fossil fuels. However, this statement is inaccurate. While fossil fuel power plants have been widely used, they come with their own set of safety and environmental concerns. The combustion of fossil fuels contributes to air pollution, greenhouse gas emissions, and climate change. These issues pose significant risks to human health and the environment. Claiming that fossil fuel power generation is relatively safe is not supported by scientific evidence and overlooks the potential benefits of transitioning to cleaner and more sustainable energy sources.

(E) The risks of unsafe disposal of waste from nuclear power plants lie in the future, but the benefits from such plants are in the present.

Option (E) highlights a temporal imbalance between the risks and benefits associated with nuclear power plants. The risks of unsafe disposal of nuclear waste are long-term and can have consequences for future generations. On the other hand, the benefits of nuclear power plants, such as electricity generation and reduced greenhouse gas emissions, are realized in the present. The proposal fails to account for this imbalance by suggesting the immediate shutdown of nuclear plants without adequately addressing the long-term risks associated with the waste. Thus, this option correctly identifies a temporal mismatch in the proposal's approach.