Questions & explanations
1. The statement 'The new policy will reduce costs' plays which of the following roles in the argument?
- It is the main conclusion of the argument.
- It is a premise supporting the conclusion that the policy should be implemented.
- It is a counterpoint to the employees' concerns.
- It is an assumption that is not explicitly stated.
- It is a subsidiary conclusion that supports the main conclusion.
Answer: It is the main conclusion of the argument.
The argument states that the policy will reduce costs and then concludes that it should be implemented. However, the statement 'The new policy will reduce costs' is the main conclusion because the rest of the argument (the recommendation to implement) is based on it. The word 'therefore' typically introduces a conclusion, but here it introduces the recommendation, making the cost reduction the underlying conclusion. In GMAT logic, the statement that the policy reduces costs is the conclusion that the argument seeks to establish, and the recommendation is a separate action based on that conclusion.
2. Which of the following, if true, would make the conclusion logically valid?
- All risk-takers are successful entrepreneurs.
- No financially literate person is a risk-taker.
- Some successful entrepreneurs are not wealthy.
- All risk-takers are wealthy.
- Some wealthy people are not risk-takers.
Answer: Some successful entrepreneurs are not wealthy.
The argument attempts to deduce that some successful entrepreneurs are not financially literate. From the premises, we know all successful entrepreneurs are risk-takers, and some risk-takers are not wealthy. To conclude that some successful entrepreneurs are not financially literate, we need a link: if some successful entrepreneurs are not wealthy, then since all wealthy are financially literate, those non-wealthy entrepreneurs are not financially literate. Option c provides that some successful entrepreneurs are not wealthy, making the deduction valid.
3. Which of the following is an error in the reasoning above?
- It confuses a necessary condition with a sufficient condition.
- It assumes that hiring more employees is always beneficial.
- It fails to consider that profits might rise for other reasons.
- It incorrectly reverses the direction of a conditional statement.
- It uses a chain of conditionals that is logically valid.
Answer: It uses a chain of conditionals that is logically valid.
The reasoning is logically valid. The argument presents a chain: if training, then productivity increase; if productivity increase, then profits rise; if profits rise, then hire more. By transitivity, if training, then hire more. There is no error; the conclusion follows logically. Option e correctly states that the chain is valid, but the question asks for an error; since there is none, the answer is that the reasoning is valid. However, among the options, only e indicates no error. The other options describe potential errors that are not present.
4. Which of the following, if true, would most strengthen the conclusion that it is not the case that no risk-takers are successful entrepreneurs?
- Some risk-takers are successful entrepreneurs.
- All risk-takers are successful entrepreneurs.
- No risk-takers are successful entrepreneurs.
- Some successful entrepreneurs are not risk-takers.
- All successful entrepreneurs are not risk-takers.
Answer: Some risk-takers are successful entrepreneurs.
The conclusion is 'it is not the case that no risk-takers are successful entrepreneurs,' which is logically equivalent to 'some risk-takers are successful entrepreneurs.' The argument already states that all successful entrepreneurs are risk-takers, but that does not guarantee that any risk-taker is a successful entrepreneur. Option a directly affirms the conclusion and strengthens it by providing evidence that there is at least one risk-taker who is a successful entrepreneur.
5. Which of the following, if true, would most weaken the conclusion?
- The study participants who drank more coffee also exercised more frequently.
- Coffee contains antioxidants that are known to reduce inflammation.
- The study was conducted over a period of 10 years.
- Participants who drank less coffee were more likely to smoke.
- The study controlled for age and gender.
Answer: The study participants who drank more coffee also exercised more frequently.
The conclusion that coffee reduces heart disease risk is weakened if there is an alternative explanation for the lower risk. Option a suggests that the coffee drinkers also exercised more, which could account for the lower risk. This introduces a confounding variable. Options b and c support the conclusion, d strengthens by showing a difference that might otherwise explain the result, and e shows control, which strengthens.
6. Which of the following can be logically deduced from the statements above?
- The company did not invest in employee training last quarter.
- The company's productivity did not increase last quarter.
- The company invested in employee training, but productivity did not increase.
- If the company's profits had risen, then productivity would have increased.
- The company's profits did not rise because productivity did not increase.
Answer: The company did not invest in employee training last quarter.
We have two conditionals: If training → productivity increase, and if productivity increase → profits rise. By transitivity, if training → profits rise. Since profits did not rise, we can deduce that training did not occur (modus tollens). Option a is correct. Option b is not necessarily true because productivity could have increased without leading to profit rise due to other factors, but the deduction is about training.
7. The reasoning in the argument is flawed because it
- assumes that if most mammals are warm-blooded, then all mammals are warm-blooded.
- concludes that some mammals lack a property that all warm-blooded animals have, based on a premise about non-mammals.
- mistakes a sufficient condition for a necessary condition.
- uses the term 'high metabolic rate' in two different senses.
- draws a conclusion that contradicts the premise that all warm-blooded animals have a high metabolic rate.
Answer: concludes that some mammals lack a property that all warm-blooded animals have, based on a premise about non-mammals.
The premises state: most mammals are warm-blooded; all warm-blooded have high metabolic rate; some high metabolic rate animals are not mammals. The conclusion that some mammals do not have a high metabolic rate does not follow. The fact that some non-mammals have high metabolic rate does not imply that some mammals lack it. The flaw is that the argument incorrectly infers about mammals from information about non-mammals.
8. Which of the following, if true, would most weaken the researchers' conclusion?
- Acupuncture involves inserting needles into specific points on the body, which can cause minor bleeding.
- The placebo group received sham acupuncture using retractable needles that did not penetrate the skin.
- The study was double-blind, with neither patients nor practitioners knowing who received real acupuncture.
- Patients in the acupuncture group also received physical therapy, while the placebo group did not.
- Acupuncture has been used for centuries in traditional Chinese medicine.
Answer: Patients in the acupuncture group also received physical therapy, while the placebo group did not.
The conclusion that acupuncture is effective relies on the comparison between the acupuncture group and the placebo group. If the acupuncture group also received an additional treatment (physical therapy) that the placebo group did not, then the observed pain reduction could be due to that extra treatment rather than acupuncture. This introduces a confounding variable, weakening the conclusion.
9. If the statements above are true, which of the following must also be true?
- Some senior employees are not eligible for the training program.
- All employees who have completed the prerequisite course are eligible for the training program.
- No employee who has not completed the prerequisite course is eligible for the training program.
- All employees eligible for the training program have completed the prerequisite course.
- Some senior employees have completed the prerequisite course.
Answer: All employees eligible for the training program have completed the prerequisite course.
"All but the most senior" means all except the most senior are eligible. "None except those who have completed the prerequisite course may enroll" means only those who completed the prerequisite can enroll. Thus, anyone eligible (except possibly the most senior) must have completed the prerequisite. Since the most senior are not eligible, all eligible employees have completed the prerequisite.
10. Which of the following can most properly be inferred from the information above?
- Extracurricular activities cause improved academic performance up to a point, after which they cause decline.
- Students who participate in extracurricular activities for 10-20 hours per week have higher GPAs than those who participate for fewer than 5 hours.
- The study's conclusion is supported by the data because the relationship is linear.
- The study proves that extracurricular activities are beneficial for all students.
- The difference in GPA between the 10-hour and 5-hour groups is statistically significant.
Answer: Students who participate in extracurricular activities for 10-20 hours per week have higher GPAs than those who participate for fewer than 5 hours.
The passage states that the 10+ hour group had a 3.5 GPA and the <5 hour group had a 3.2 GPA. Since 10-20 hours is a subset of 10+ hours, and the 10+ group includes those up to 20 hours, it is reasonable to infer that the 10-20 hour group had a GPA at least as high as the 10+ group average, which is higher than the <5 group. This is a valid inference from the comparison.
11. Which of the following is an assumption necessary for the conclusion to be properly drawn?
- All successful managers have strong communication skills.
- Jane is a manager.
- Strong communication skills are the only requirement for being a successful manager.
- Jane has been a manager for at least five years.
- People with strong communication skills are always successful managers.
Answer: All successful managers have strong communication skills.
The argument states that to be a successful manager, one must have strong communication skills. This is a necessary condition. The conclusion that Jane has strong communication skills follows from the premise that she is a successful manager only if the premise is interpreted as 'all successful managers have strong communication skills.' This is the necessary assumption.
12. Which of the following is a flaw in the reasoning above?
- It assumes that the companies in the study are representative of all companies.
- It confuses correlation with causation.
- It draws a conclusion that is too broad based on a limited sample.
- It overlooks the possibility that the five-day workweek companies may have had other factors affecting productivity.
- It fails to consider that the productivity increase might be due to the novelty effect.
Answer: It draws a conclusion that is too broad based on a limited sample.
The argument concludes that 'any company' switching to a four-day workweek will see a significant boost, based on a study of 500 companies. This is an overly broad generalization; the sample, though large, may not be representative of all companies across different industries, sizes, and contexts. The flaw is that the conclusion is too broad for the evidence provided.