Logical Reasoning Sample Questions 1 – 3

This question asks you to identify the point on which Laird and Kim disagree with respect to pure research. Laird identifies two contributions of pure research: its medical applications (“technologies that contribute to saving lives”) and its role in expanding knowledge and providing new ideas. Of these, Laird considers the second contribution to be more worthwhile. Kim, on the other hand, maintains that “Saving lives is what counts most of all.” Since pure research saves lives through medical applications, Kim disagrees with Laird about whether pure research has its most valuable achievements in medical applications. The correct response, therefore, is (D). 

Response (A) is incorrect since we can determine, based on their statements, that Laird and Kim agree that pure research “derives its significance in part from its providing new technologies.” Laird explicitly cites the value of pure research with respect to providing new technologies. Kim indicates agreement with (A), at least in the case of medical technologies, by asserting that “Without pure research, medicine would not be as advanced as it is.” 

Response (B) is incorrect since we can determine, based on their statements, that Laird and Kim would likely agree that pure research “expands the boundaries of our knowledge of medicine.” Laird notes that pure research provides us with new technologies that have medical applications. Kim points out that “Without pure research, medicine would not be as advanced as it is.” 

Response (C) is incorrect. Kim indicates agreement that pure research “should have the saving of human lives as an important goal” since Kim’s position is that “Saving lives is what counts most of all.” Since Laird cites the saving of lives as one way in which pure research is worthwhile or valuable, Laird also indicates agreement that pure research “should have the saving of human lives as an important goal,” although Laird indicates that expanding knowledge and providing new ideas should be an even more important goal of pure research. The same activity can of course have more than one goal. 

Response (E) is incorrect. Laird clearly agrees that pure research has value “apart from its role in providing new technologies to save lives,” given that Laird explicitly cites a second way in which pure research is valuable. However, nothing in what Kim says suggests disagreement with (E). Kim’s position is that the greatest value of pure research is its role in providing new technologies to save lives. We cannot infer from this that Kim believes this role to be the only value of pure research. 

This question was of medium difficulty, based on the number of test takers who answered it correctly when it appeared on the LSAT. 

This question asks you to identify how the executive’s reasoning proceeds. The ads discussed by the executive appeared in two places—in a magazine and on the magazine’s website. Some information is available concerning the effect of the website ads on consumers, but no consumer response information is available about the print ads. The executive’s remarks suggest that the ads that appeared in print and on the website were basically the same, or very similar. The executive reasoned that information about the effect of the website ads could be used as evidence for an inference about how the print ads likely performed. The executive thus used the analogy between the print ads and the website ads to infer something about the print ads. (D), therefore, is the correct response. 

Response (A) is incorrect. The executive’s conclusion about the likely consumer response to the print ads does not constitute a prediction, but rather a judgment about events that have already transpired. Moreover, the executive’s conclusion is not based on any reasoning about the cause of the consumer response to the print ads. 

Response (B) is incorrect. The executive does conclude that certain events are likely to have transpired on the basis of what was known to have transpired in a similar case, but no distinction can be made in the executive’s argument between events of a general kind and a particular event of that kind. There are two types of events in play in the executive’s argument and they are of the same level of generality—the response to the website ads and the response to the print ads. 

Response (C) is incorrect. The executive does not infer a statistical generalization, which would involve generalizing about a population on the basis of a statistical sample. The executive merely draws a conclusion about the likely occurrence of specific events. 

Response (E) is also incorrect. The executive does use the comparability of the print and website ads as the basis for the conclusion drawn; however, as noted above, the executive’s conclusion about the likely consumer response to the print ads does not constitute a prediction about future events, but rather a judgment about events that have already transpired. 

This was an easy question, based on the number of test takers who answered it correctly when it appeared on the LSAT. 

The question asks you to identify the response that can be properly inferred from the passage. The passage indicates that the Quebec Bridge disaster in 1907 and the inquiry that followed caused the engineering “rules of thumb” used in construction of thousands of bridges to be abandoned. Since the Quebec Bridge disaster in 1907 prompted this abandonment, it can be inferred that these were the rules of thumb under which the Quebec Bridge was being built when it collapsed and that these were the rules of thumb used in bridge building before 1907. Further, since the Quebec Bridge collapsed while under construction and the rules of thumb being used were abandoned as a result, it can be inferred that the rules of thumb used in building the Quebec Bridge and bridges prior to 1907 were insufficient to completely assure the safety of bridges under construction. Finally, since the alternative that was adopted in place of the old engineering rules of thumb was to “depend on far more rigorous applications of mathematical analysis,” it can be inferred that the mathematical analysis incorporated in the engineering rules of thumb used prior to 1907 made them insufficient to completely assure the safety of bridges under construction. Thus, (E) is the correct response. 

Response (A) is incorrect. (A) asserts that bridges built before about 1907 were unsafe for the public to use because they were built without thorough mathematical analysis. But this conclusion goes far beyond what is established by the passage. The passage gives evidence only about the safety of bridges built before 1907 while they were under construction. It is silent on whether bridges built before about 1907 were safe when open for use by the public. Moreover, the passage indicates that the rules of thumb used in bridge construction before 1907 were abandoned because the use of those rules did not provide adequate assurance of safety for bridges under construction. It does not follow that bridges built using those rules of thumb (those built before about 1907) actually were unsafe, either while under construction or when open for public use. 

Response (B) is incorrect in claiming that Cooper’s absence from the construction site caused the breaking off of the cantilever. The passage does not establish that, had Cooper been at the site, he could have successfully intervened to prevent the cantilever from breaking off. By freezing the project, he might have spared lives by stopping work, but there is nothing in the passage to indicate that he necessarily would have prevented the collapse. 

Response (C) is incorrect; there is no evidence in the passage about why nineteenth-century bridge engineers relied on their rules of thumb. 

Response (D) is also incorrect. While the passage suggests that a more rigorous application of mathematical analysis would have prevented the collapse of the bridge, it offers no evidence that it is the only way the collapse could have been prevented. For example, it might have been prevented had corrective measures been taken in time. 

This question was of medium difficulty, based on the number of test takers who answered it correctly when it appeared on the LSAT.