LSAT-Section-1-Logical-Reasoning Section One : Logical Reasoning - Practice Questions

Question 61

Columnist: It is impossible for there to be real evidence that lax radiation standards that were once in effect at nuclear reactors actually contributed to the increase in cancer rates near such sites. The point is a familiar one: who can say if a particular case of cancer is due to radiation, exposure to environmental toxins, smoking, poor diet, or genetic factors.

The argument's reasoning is most vulnerable to criticism on which one of the following grounds?

Select an option, then click Submit answer.

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The argument fails to recognize that there may be convincing statistical evidence even if individual causes cannot be known.
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The argument inappropriately presupposes that what follows a certain phenomenon was caused by that phenomenon.
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The-argument inappropriately draws a conclusion about causes of cancer in general from evidence drawn from a particular case of cancer.
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The argument ignores other possible causes of the increase in cancer rates near the nuclear reactor complexes.
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The argument concludes that a claim about a causal connection is false on the basis of a lack of evidence for the claim.

Reference / correct answer:

The argument fails to recognize that there may be convincing statistical evidence even if individual causes cannot be known.

Once again, an argument author is using faulty logic; no big surprise there. The columnist concludes that it is “impossible” for there to be evidence that lax radiation standards at nuclear reactors actually contributed to the increase in cancer rates near those sites. And the columnist’s evidence that it is impossible for there to be such evidence? Simply the fact that no one can say if a particular case of cancer is due to radiation, smoking, or other factors. Did you notice the scope shift there? Many flawed arguments turn on such subtle scope shifts. In this instance the columnist takes evidence about what may have caused a single case of cancer and uses it to support a conclusion about whether there is evidence that radiation contributed to an increase in cancer rates. Therefore, you should have been looking for an answer choice that addresses this scope shift. Option [The argument fails to recognize that there…] does the job. If, for instance, there were statistical evidence that cancer rates had increased by 80 percent during the relevant time period, that would be evidence that the standards had made a contribution, even if you couldn’t prove conclusively that any one of the individual cases was due to radiation.

Question 62

Some planning committee members' those representing the construction industry – have significant financial interests in the committee's decisions. No one who is on the planning committee lives in the suburbs, although many of them work there.

If the statements above are true, which one of the following must also be true?

Select an option, then click Submit answer.

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No persons with significant financial interests in the planning committee's decisions are not in the construction industry.
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No person who has a significant financial interest in the planning committee's decisions lives in the suburbs.
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Some persons with significant financial interests in the planning committee's decisions work in the suburbs.
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Some planning committee members who represent the construction industry do not work in the suburbs.
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Some persons with significant financial interests in the planning committee's decisions do not Jive in the suburbs.

Reference / correct answer:

Some persons with significant financial interests in the planning committee's decisions do not Jive in the suburbs.

Two sentences here, one beginning with the word “Some,” the other with “No one.” Add to that an Inference stem and answer choices that begin with either “No” or “Some” and the result is unmistakable – this is classic formal logic. It’s possible to combine the statements, just like we do in Logic Games, in order to deduce what must be true. The two most helpful terms in the short stimulus are “some” and “no one” – the former we understand to mean “at least one,” while the latter excludes all members of a group from a particular situation. “Many” is simply not as helpful, because we have no way of telling which people this “many” refers to. So it’s a good strategy to look to combine the first sentence with the first part of the second sentence. Were you able to do this? If so, you should have had no trouble scanning for the correct answer. If not, try it now before reading on. Okay: The first sentence tells us that at least one planner/construction rep (nothing wrong with shortening the terms to that) has an interest in the decisions. But no planner lives in the suburbs, so if we combine these facts, we can say conclusively that there must be at least one non-suburbanite (the planner from above) who has an interest in the decisions. That’s the same as saying that some (at least one) persons interested in the decision don’t live in the suburbs, choice [Some persons with significant … do not Jive in the suburbs.]. You may have noticed another deduction: It must be true that some construction reps don’t live in the suburbs, since the planners in question, none of whom live in the suburbs, are “those representing the construction industry.”

Question 63

Arbitrator: The shipping manager admits that he decided to close the old facility on October 14 and to schedule the new facility's opening for October 17, the following Monday. But he also claims that he is not responsible for the business that was lost due to the new facility's failing to open as scheduled. He blames the contractor for not finishing on time, but he, too, is to blame, for he was aware of the contractor's typical delays and should have planned for this contingency.

Which one of the following principles underlies the arbitrator's argument?

Select an option, then click Submit answer.

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A manager should take foreseeable problems into account when making decisions.
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A manager should be able to depend on contractors to do their jobs promptly.
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A manager should see to it that contractors do their jobs promptly.
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A manager should be held responsible for mistakes made by those whom the manager directly supervises.
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A manager, and only a manager, should be held responsible for a project's failure.

Reference / correct answer:

A manager should take foreseeable problems into account when making decisions.

Next up is the tale of the shipping manager, as told by The Arbitrator. The question stem instructs us to locate a principle underlying the argument, so we’d be well served to read the argument with an eye towards forming a general paraphrase. The arbitrator tells of a shipping manager who admits to making a decision (close the old facility on the 14th, open the new on the 17th). But he shirks responsibility for the consequences of this decision (the new facility failed to open on time; business was lost). He shifts the blame, but the arbitrator concludes that he too is responsible because he was aware of possible delays and should have planned ahead for them. It’s very difficult to predict the principle we seek word for word, but we can look for something that speaks to personal responsibility stemming from a proactive awareness of the various angles of a situation. In other words: plan ahead, or don’t complain when things go wrong. And that’s what we get in option [A manager should take foreseeable problems…]: The “typical delays” were foreseeable, and by insisting that the manager take some blame for the lost business, the arbitrator acts according to the principle that such foreseeable circumstances should be taken into account by a manager when making decisions. Option [A manager should take foreseeable problems…] states in general terms what the arbitrator specifically says: The manager should have known there may have been a delay when he made the decision to close the old plant, and therefore he should own up to part of the blame.

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