LSAT-Section-1-Logical-Reasoning – Section One : Logical Reasoning

Reference / correct answer:

Argument construction

Henry tells us that:

An average American car driver drives a thousand miles per month.

- So, if all American car drivers drove only five miles less daily, their monthly mileage would reduce by 15 percent (5 × 30 = 150 miles = 15% of 1000 miles). Five miles is ten thousand steps, the amount of daily walking recommended by doctors for good health.

Therefore, if the government can persuade car drivers to drive five miles less daily and walk that distance instead, the total transport-related carbon emissions in the United States would reduce by 15 percent.

Bill responds to Henry by saying that cars are responsible for only 30 percent of all transport-related carbon emissions in the United States.

Understanding how the argument proceeds Let's dissect the argument.

When we strip Henry's argument to its essence, it is this:

'Reducing average monthly mileage of American car owners by 15 percent would reduce the total transport-related carbon emissions in the United States by 15 percent.'

So, Henry is assuming that only car owners are responsible for transport-related carbon emissions in the United States. In his mind, the formula for transport-related carbon emissions is:

(Total transport-related carbon emissions per month) = (Average carbon emissions made per car mile) × (Average monthly miles driven per driver) × (Number of drivers)

Note that the right-hand side of this equation would give 'total car-related carbon emissions per month'. Henry assumes that this number is equal to 'total transport-related carbon emissions per month'.

By pointing out that total car-related carbon emissions are, in fact, only 30 percent of all transport-related carbon emissions in the United States, Bill is telling Henry that his assumption was mistaken. And due to this mistake, Henry's argument is incorrect.

Let's analyze each option one by one.

Answer choices explanation

[refuting an assumption on which Henry's argument relies] This is correct. It accords with the discussion done in the argument analysis above.

[discrediting Henry's argument by giving of erroneous information] This is incorrect. We have no reason to decide that the information given by Bill is erroneous.

[arguing that the benefit of Henry's hypothetical measure might also be achieved in another way] This is incorrect. The benefit of Henry's hypothetical measure is a 15 percent reduction in the total transport-related carbon emissions in the United States. Bill suggests no other way to achieve this benefit.

[citing seemingly irrefutable evidence that contradicts one of the stated premises on which Henry's argument depends] This is incorrect. The stated premises on which Henry's argument depends are: If all American car drivers drove only five miles less daily, their monthly mileage would reduce by 15 percent. Five miles is ten thousand steps to walk. (The argument also makes use of an unstated premise (that is, an assumption): all transport-related carbon emissions in the United States are made by cars.) Bill's response does not contradict either of the two stated premises listed above. Further, Bill cites evidence that contradicts Henry's claim, not a premise.

[providing additional information in support of Henry's argument] This is incorrect. As discussed in the analysis section above, Bill's response does not support Henry's argument.

Reference / correct answer:

Argument construction

Tony says that most web-pages on the internet have multiple enticing and hard-to-ignore hyperlinks. Each of these links leads to further hyperlinks and so on. This chain of 'link 1 leading to link 2 leading to link 3…' creates, in Tony's words, a "bottomless hole of distracting and mostly trivial information." He says that regularly falling into this hole decreases the ability of heavy internet users to do complex reasoning that requires focus and attention.

James responds by citing a research study that found that heavy internet users did better than infrequent users on tests for attention and also had higher levels of activation in the brain areas associated with complex reasoning.

Understanding the point at issue

We need to understand each person's stance clearly to understand the point at issue.

Tony's stance essentially is: Heavy internet usage decreases the ability to do complex reasoning that requires focus and attention.

○ Prior to declaring this stance, he explains how the internet is full of enticing links that lead you to tons of distracting information.

○ He implies that regularly falling into the temptations of internet would decrease a heavy internet user's attention span and ability to focus, and since these two are required to do complex reasoning, these user's ability to do complex reasoning would decrease.

James' stance essentially is: Heavy internet users have better ability to focus and attention and also seem to be more actively doing complex reasoning than infrequent internet users.

○ He cites a research study's findings to support his claim.

Therefore, the point at issue between Tony and James is whether heavy internet usage decreases a person's ability to do complex reasoning or not. Tony says 'Yes' and James says 'No.'

Let's analyze each option one by one.

Answer choices explanation

[focus and attention are necessary to do complex reasoning] This is incorrect. Tony explicitly states that focus and attention are necessary to do complex reasoning. As far as James is concerned, the research finding cited by him shows better 'focus and attention' and also more frequent complex reasoning in heavy internet users. Therefore, James too seems to believe that there is at least a correlation between 'focus and attention' and 'complex reasoning.' Since he does not actively rebut Tony on this matter, this is certainly not a bone of contention – the point at issue – between the two.

[most web-pages on the internet require internet users to do complex reasoning] This is incorrect. Tony implies that most web-pages on the internet offer distracting information. Since he believes that complex reasoning requires focus and attention (the opposites of distraction), he might also believe that most web-pages on the internet do not require users to do complex reasoning. James' argument is that heavy internet users do complex reasoning more frequently than infrequent users. We cannot infer from this that James believes that most web-pages on the internet require such skills. James might believe, for example, that heavy internet users are more likely than infrequent users to visit certain specific web-pages that require users to do complex reasoning. Therefore, we cannot infer whether James supports or opposes this option statement. Since we don't even know for sure what James thinks about it, this option certainly is not the point at issue between him and Tony.

[most web-pages on the internet have hard-to-ignore hyperlinks] This is incorrect. Tony explicitly supports this statement. However, nothing that Tony says commits him to a particular view on this statement. There is certainly no indication that the two hold opposing views on this matter.

[heavy internet usage decreases a person's ability to do complex reasoning] This is correct. It is in-line with our discussion in the 'Argument Construction' section.

[heavy internet users are more knowledgeable than infrequent internet users] This is incorrect. 'Knowledge' and 'information' are two distinct entities. While Tony does seem to imply that heavy internet users access more information on the internet than infrequent users, he does not touch at all the question of how much, if at all, this extra information improves the knowledge of heavy internet users. James is silent on both the relative information consumption and the relative knowledge of heavy and infrequent users. Therefore, it is not possible to deduce the stance of either Tony or James on this option statement.

Reference / correct answer:

Argument construction

The annual Livability Ranking (published by Urban Intelligence Unit) ranks 100 American cities for their quality of life based on assessments of:

urban infrastructure healthcare education crime rates culture сlimate.

However, this ranking should also consider unemployment rates.

Reason - If a city is unable to offer work opportunities to a sizeable proportion of its population that needs to work for survival, the quality of life for that proportion would be abysmal.

Understanding the role played by the claim Let's dissect the argument.

The first step in analyzing this argument is identifying the conclusion. To do this, let's find the position for which the argument offers support.

From the first sentence, we know that Rankings are based on quality of life.

The same sentence lists six factors that are assessed in determining the quality of life.

The last sentence begins with the phrase 'After all,' which indicates that the statement that follows it is a premise. This premise, simply put, is that high unemployment rate means poor quality of life.

When we put this sentence in conjunction with the first sentence, we see that the argument is constructed to support the position stated in the second sentence: "… [the Livability] ranking should also consider unemployment rates."

Thus, the claim "this ranking should also consider unemployment rates" asked about in the question is the conclusion of the argument.

Let's analyze each option one by one. Answer choices explanation

[It offers a reason to support the conclusion.] This is incorrect. The claim is not an explanation or a reason-giving-statement.

[It is an assertion that refutes the conclusion.] This is incorrect. The claim does not refute any statement in the argument.

[It is a principle from which the conclusion is derived.] This is incorrect. The claim does not act as the source (principle) of any further conclusion.

[It is a premise of the argument.] This is incorrect. As discussed in the 'Argument Construction' section, the premises of the argument are contained in the first and the third sentences of the argument. The claim is not a premise.

[It is a conclusion of the argument.] This is correct. It is in-line with our discussion in the 'Argument Construction' section.