LSAT Logical Reasoning › Determining which answer most accurately expresses the main idea of the argument
Doctor: A major study found no causal link between having received an MMR vaccine and having autism, but the study is flawed. The study looked at 500 people who had received an MMR vaccine. Because autism occurs in less than 1% of the population, researchers would need to include many more than 500 people in a study to detect a meaningful increase in the rate of autism.
Which of the following most accurately expresses the main conclusion of the doctor's argument?
A major study that discovered no causal relationship between the MMR vaccine and autism is unreliable.
Contrary to the findings of a major study, there is reason to believe that the MMR vaccine causes autism.
Medical professionals should conduct more research into the MMR vaccine to determine whether it is causally linked with autism.
The major study cited does not reach a conclusion as to whether autism results from the MMR vaccine.
Researchers cannot determine whether a given disorder is causally linked to a procedure if the base rate for the disorder is less than 1%.
The passage begins with a fact and the judgment that the study is flawed. The rest of the paragraph explains how it's flawed (i.e., not enough people were included in the study to justify the conclusion). Therefore, the correct answer is the first sentence, because everything else in the passage supports that claim.
It is a costly, needless error to require extensive training for all medical professionals. Some perform complex surgeries and some eye exams, but all are required to receive broad training. If training requirements were more appropriately adapted to particular jobs within the medical field, many medical professionals could more easily become certified to practice and would charge less for their services.
The author of the passage is most likely to agree with which of the following?
All medical professionals are currently required to receive broad training
All medical professionals are currently required to receive the same training
Many medical professionals receive broader training than they need, but this is preferable to the risk of too little training
The jobs performed by most medical professionals should not require extensive training
There would be no negative effects from reducing the training required for many medical professionals
The passage expressly states that all medical professionals are required to receive broad training. The author does not express agreement with any of the other statements.
Consultant: While most businesspeople are concerned about customers taking off with their merchandise or suppliers overcharging them, the actions of their employees often go overlooked. Yet because an employee can bilk small amounts from a company with little notice, a persitent thieving employee can amass a large amount of stolen money simply by being able to do it over a long period of time.
Which of the following best summarizes the consultant's main point?
The biggest threat to small business owners is theft by their own employees.
Many suppliers cheat and swindle small business owners without the owner catching on to the deception.
Most small business owners are incredibly vigilant about customers taking off with their merchandise or suppliers overcharging them.
Theft from small business owners is much easier than theft from large corporations due to lax standards.
Theft by customers and overcharging by suppliers is not a significant problem for small business owners.
The argument centers on the issue of theft from small businesses by employees. It is important that this issue is compared to the typically thought of ways people steal from small businesses and that theft by employees is much more prominent and problematic than theft by customers and cheating by suppliers.
80% of families own a pet of some variety. The Jones family has three cats and two dogs, but none of them are technically pets. All of their animals live outside, and no true pet sleeps outdoors.
Which of the following best expresses the main conclusion of the above passage?
The Jones family does not have pets.
No true pet sleeps outdoors.
80% of families own a pet of some variety.
The Jones family has three cats and two dogs.
The Jones family does not allow animals inside their home.
The first sentence is merely background information. Sentence two offers the main conclusions of the passage, as supported by the premises given in sentence three.
Technology expert: Many people believe that smartphones are getting too big nowadays. They argue that portability is more important than screen size, and that if a person wants a huge screen, he or she should buy a tablet rather than a smartphone. But these arguments ignore current sales data. In the last three years, the best-selling new phones have consistently had screen sizes half an inch to an inch larger than their competitors. Bigger, it seems, is still better in the eyes of consumers.
Which one of the following most accurately expresses the main conclusion of the technology expert’s argument?
Those arguing that portability in smartphones is more important than screen size fail to take current sales data into account.
Most consumers believe that bigger smartphones are more practically useful than smaller ones.
Many people believe that smartphones are too large.
The best-selling new phones have consistently larger screens than their competitors.
Tablets and smartphones are beginning to have overlapping markets.
The argument’s conclusion is found in the third sentence: “these arguments (i.e. the arguments of those who believe portability is more important than screen size) ignore current sales data.” The remaining answer choices either restate premises of the argument, or contain extrapolated statements not contained in the passage.
While coffee does stain teeth, most claims that coffee has ill-effects are unfounded. There is even some evidence of health benefits. The situation may be different when the arguments relate to people who consume more than a moderate amount of coffee.
Which of the following conclusions most logically follows from the argument?
Many purported ill-effects from moderate consumption of coffee are unfounded
Consumed in moderation, coffee has no ill-effects
Moderate coffee consumption will not stain teeth
People who drink coffee in excess are likely to have severe teeth staining
Moderate consumption of coffee has health benefits while excessive consumption causes ill-effects, including teeth staining
The argument does not draw a strong conclusion. It does not assert that coffee is healthy or that it has no negative health effects.
Professor: I cannot agree with the common sentiment that there should be fewer math requirements for children. While few children will directly use math for their careers, studying math strengthens important skills. Through math classes, children learn to follow complex instructions, reason, and confirm results. These skills are valuable for life and careers. Besides, most other subjects that children learn are also only indirectly useful.
Which of the following best expresses the professor's main point?
Children gain valuable skills by studying math even when they do not directly use math in their careers
There should be no changes to math requirements for children
Through math, children learn skills that they cannot learn in other ways
Most subjects teach children fewer skills than math
Those who suggest that children should have fewer math requirements underestimate how often children will directly use math in their careers
The professor concedes that children are unlikely to directly use math in their careers. The professor's main point is that math produces skills that are indirectly useful. Further, while the above argument is a response to those who would reduce math requirements, it is not clear precisely what the professor believes are the appropriate requirements.
Director of the transportation department: We could save money over the next few years by closing lanes on highways and deferring repairs. The cost savings would be well worth the moderate increase in traffic jams. The roads will eventually need to be repaired, but the department could stay within budget over the next several years, which should be a top priority. If we continue to overspend, we may face a financial disaster.
Assistant director: Closing road lanes would lead not only to a considerable increase in traffic jams but would also lead to increased accidents and death. That said, we’ve explored other options and closing the lanes seems to be our only viable plan to save money, and there is no question that we must accomplish that.
The Director's main point is which of the following?
The department should close road lanes for several years to save money
The department should close road lanes for several years for safety reasons
Paying for road repairs causes the department to spend above its budget
Road lane closures leads to only a moderate increase in traffic jams
The department should be able to afford repairs in a few years
The Director's main point is that road lanes should be closed in order to save money. The other statements are either support for that main point or in conflict with the Director's argument.
Eye surgery has become a viable alternative to wearing glasses. There have been questions about long term effectiveness for many years, but the doubt seems to be disappearing. Few people have reported negative effects even years after surgery and many people say their improved vision has lasted. We should see the demand for eye surgery increasing drastically as a result of doubts being dispelled. Yet, the number of people obtaining eye surgeries remains relatively constant.
Which of the following best describes the main point of the passage?
Since concerns about the effectiveness of eye surgery have recently been dispelled, it is surprising that eye surgeries have not become more popular
Concerns about the effectiveness of eye surgery have recently been dispelled, so these surgeries will become more common in the future
Eye surgery should be a more common alternative to glasses and contacts than it is currently
In the past, there were legitimate concerns about the effectiveness of eye surgery, but these concerns have recently been dispelled
Despite what was once thought to be the case, eye surgeries are unlikely to be a viable alternative to glasses and contacts
The purpose of the passage is to explain that it is perplexing that eye surgeries have not become more popular as a result of concerns about effectiveness being dispelled. The passage is not intended to take a position on whether eye surgery should be used more often.
The school needs to find new ways to improve its test scores. Although the school used to have a large amount of highly-qualified teachers, many of them have left to pursue other careers. Their departure has harmed the quality of instruction students receive. The school is unlikely to attract talented teachers in the near future.
Which one of the following most accurately presents the main conclusion of the passage?
The school needs to find new ways to improve its test scores.
The school needs to attract new highly-qualified teachers.
The departure of highly-qualified teachers has harmed the instruction the students receive.
The school is unlikely to attract talented teachers in the near future.
The school’s test scores are suffering.
The first sentence is the conclusion. The rest of the stimulus is mearly support for that initial conclusion.