Agree/Disagree
Strengthens/ Weakens an argument
Strengthens/ Weakens an argument
Speaker A: "The only reason large‑diesel cars aren’t more common in the U.S. is that people believe they cost more to fuel and maintain than gasoline cars."
Speaker B: "Actually, many people don’t even know diesel cars are an option, and some focus too much on purchase price even though operating cost may favor diesel."
Question: Roger and Tamara most likely disagree about which of the following?
(A) Diesel cars cost more to operate than gasoline cars.
(B) Many people in the U.S. don’t know diesel cars are an option.
(C) There is a purchase‑price difference between diesel and gasoline cars.
(D) Diesel cars last many more years than gasoline cars.
(E) Diesel cars aren’t commonly used because people believe they cost more to operate.
(E).
Explanation: Speaker A claims only the belief about higher operating/maintenance cost is the reason diesel cars aren’t common. Speaker B counters that there are other reasons: ignorance of the option, overemphasis on purchase price, etc. So the point of disagreement is over whether the belief about cost is the sole reason. Choice (E) captures that direct disagreement.
Stimulus:
All employees at Firm X who complete the management training are promoted within a year.
Jessica was promoted within six months of being hired.
Question: The argument assumes which of the following?
(A) Jessica completed management training.
(B) All promoted employees completed training.
(C) Jessica was hired as a manager.
(D) Jessica is the only one promoted that quickly.
(E) Management training is required for promotion.
✅ Answer: (A)
Explanation: The argument links promotion to training, then uses Jessica's promotion as evidence. It assumes she did the training.
A recent study found that customers who switched to Brand X toothpaste reported fewer cavities over a year.
Therefore, Brand X toothpaste must be better at preventing cavities than any other toothpaste.
Which of the following indicates a flaw in the argument's reasoning?
A. It assumes that Brand X users had worse dental health to begin with.
B. It takes a correlation to be evidence of a causal relationship.
C. It overlooks the possibility that Brand X was used improperly.
D. It presumes that all users of Brand X used the same brushing technique.
E. It fails to consider that the results were not statistically significant.
✅ Correct Answer: B
🟨 Explanation:
The argument commits a classic causal flaw — it assumes that because switching to Brand X happened before the decrease in cavities, it caused the decrease. But the drop in cavities could be due to other factors (e.g., better brushing, flossing, or dental visits). Correlation ≠ causation. Answer: B
Every student who passed the final exam also completed all the practice tests.
Jamie passed the final exam.
Therefore, Jamie must have completed all the practice tests.
Which one of the following, if assumed, would allow the conclusion to be properly drawn?
A. Students who do not pass the final exam have not done the practice tests.
B. Jamie is one of the best students in the class.
C. Completing the practice tests improves chances of passing.
D. All students who passed also completed the practice tests.
E. Jamie studied with a group that completed all practice tests.
✅ Correct Answer: D
🟨 Explanation:
To justify the conclusion that Jamie completed all practice tests, we need to connect "passing the final" with "having done the practice tests."
Answer D provides exactly that connection — if all who passed completed them, and Jamie passed, then Jamie must have completed them. This makes the conclusion logically valid.
All of the actors in the play are members of the theater club.
Some members of the theater club are not actors in the play.
Question:
If the statements above are true, which one of the following must also be true?
A. All members of the theater club are actors in the play.
B. Some actors in the play are not members of the theater club.
C. No members of the theater club are actors in the play.
D. Some members of the theater club are actors in the play.
E. All members of the theater club are not in the play.
✅ Correct Answer: D
Explanation:
We’re told all actors in the play are in the theater club → so at least some theater club members are actors → D must be true.
Speaker A: "Pure research provides new technologies that help in saving lives, but more importantly it expands knowledge and spawns new ideas."
Speaker B: "You have your priorities backwards: saving lives is what matters most. Without pure research, medicine wouldn’t be advanced, but that’s a means to the end of saving lives."
Question: Laird and Kim disagree over whether pure research ___
(A) should be prioritized for its ability to expand human knowledge over its ability to save lives.
(B) has ever resulted in saveable lives.
(C) is less important than applied research.
(D) should be funded more heavily.
(E) is undervalued by those who emphasize its practical applications.
Answer: (A).
Explanation: The key is: Speaker A values pure research especially for knowledge & idea generation (beyond saving lives). Speaker B believes saving lives is more important than idea generation, and that the value of pure research is in how it contributes to saving lives. The disagreement is about whether expanding knowledge/new ideas has greater priority vs saving lives.
New research shows students who sleep at least 8 hours perform better on exams. Therefore, increasing average student sleep time will improve academic performance.
Question: The argument assumes which of the following?
(A) Students are not already sleeping 8 hours.
(B) Performance on exams is the best measure of learning.
(C) Sleep is the only factor affecting test performance.
(D) Increased sleep causes the improved performance.
(E) Academic performance can’t improve without more sleep.
✅ Answer: (D)
Explanation: Correlation isn’t causation. To conclude that more sleep will lead to better scores, the argument must assume sleep causes the improvement.
Companies that invest heavily in employee training tend to have higher profitability.
Thus, companies seeking higher profits should invest more in training.
Which of the following identifies a flaw in the reasoning above?
A. It assumes that employee training improves long-term job satisfaction.
B. It overlooks the possibility that profitability enables investment in training.
C. It presumes that all types of training are equally beneficial.
D. It confuses an absolute increase with a relative one.
E. It fails to consider the role of external market factors.
✅ Correct Answer: B
🟨 Explanation:
The flaw is that the argument assumes the direction of causality. Just because profitable companies train more doesn’t mean training caused the profit — maybe being profitable enables companies to afford better training. This is a reversed cause-effect flaw.
Doctors who specialize in emergency care often work irregular hours.
Samantha claims that this causes increased stress, which in turn reduces job satisfaction.
Therefore, the hospital should offer more flexible scheduling to emergency care doctors.
What role does the statement “Samantha claims that this causes increased stress…” play in the argument?
A. It provides evidence that directly supports the conclusion.
B. It presents a conclusion based on the evidence about irregular hours.
C. It offers a causal link between a fact and the recommendation.
D. It anticipates an objection to the recommendation.
E. It contradicts the initial statement about emergency doctors.
✅ Correct Answer: C
🟨 Explanation:
Samantha’s claim about stress explains why irregular hours might lead to lower satisfaction, which supports the conclusion that flexible scheduling would help. It’s a causal link that connects evidence to the recommendation.
During the annual fundraiser, each guest made either a monetary donation, donated time as a volunteer, or did both.
No guest failed to contribute in some way.
Some guests did not volunteer their time.
Question:
If the statements above are true, which one of the following must also be true?
A. Every guest who volunteered also made a monetary donation.
B. No guest both donated money and volunteered.
C. Some guests made a monetary donation.
D. Every guest volunteered.
E. Some guests made no contribution.
✅ Correct Answer: C
Explanation:
Some guests didn’t volunteer — but everyone contributed in some way, so those who didn’t volunteer must have donated money → C must be true.
Paraphrase:
Speaker A: "We should ban plastic straws to reduce ocean pollution."
Speaker B: "Banning plastic straws won’t significantly reduce ocean pollution; small measures are insufficient compared to larger scale sources of plastic waste."
Question: The two speakers most likely disagree about whether:
(A) ocean pollution is a serious problem.
(B) plastic straws are harmful to marine life.
(C) banning straws will significantly reduce ocean pollution.
(D) regulation of packaging is more important than regulation of straws.
(E) all single‑use plastics should be banned.
Answer: (C).
Explanation: Both agree that ocean pollution exists and that plastic straws contribute. The disagreement is whether banning straws will significantly reduce pollution (Speaker A says yes; Speaker B says no).
Recycling plastic is expensive and energy-intensive. Therefore, a city wanting to reduce energy use and costs should stop recycling plastic.
Question: The argument depends on assuming which of the following?
(A) No alternatives to plastic recycling would save more energy.
(B) The city’s only goal is to reduce energy use and costs.
(C) Plastic recycling doesn’t reduce environmental harm.
(D) Not recycling plastic reduces more energy and costs than continuing it.
(E) Citizens will support stopping plastic recycling.
✅ Answer: (D)
Explanation: The conclusion is that stopping recycling will reduce energy and costs. That only follows if not recycling actually saves more than recycling costs.
Most coral reefs are shrinking despite protection efforts.
Therefore, governments should conclude that marine protection policies are ineffective.
Which of the following reveals a flaw in the argument?
A. It ignores that some reefs might still be expanding.
B. It fails to consider that protection efforts might not have had enough time to show results.
C. It assumes that marine protection is the only environmental policy in place.
D. It overlooks how temperature changes impact coral reefs.
E. It presumes that reef damage is the only measure of environmental success.
✅ Correct Answer: B
🟨 Explanation:
The conclusion that protection policies are ineffective assumes they’ve had enough time to work. But if the policies were implemented recently, reefs may still be shrinking even though the policies are effective long-term. This is a premature evaluation flaw.
Tasha: “No one who fails to follow safety guidelines should be allowed to operate machinery. Carl ignored the guidelines yesterday. So, Carl should not be allowed to operate machinery.”
Which of the following uses reasoning most similar to the argument above?
A. Anyone who doesn’t pay taxes shouldn’t get government benefits. Mark didn’t pay taxes, so he shouldn’t get benefits.
B. Lisa broke the dress code. Therefore, she should not be hired.
C. Jack drives recklessly. Reckless drivers cause accidents. So, Jack will cause an accident.
D. Maria missed class. Everyone who missed class failed. So, Maria failed.
E. Brian studies hard. People who study hard tend to succeed. So, Brian will succeed.
✅ Correct Answer: A
🟨 Explanation:
The original argument uses a universal rule (“No X should be allowed to do Y”) + a case that meets the condition (Carl is X) → conclusion (Carl should not do Y).
Choice A follows the same structure: universal prohibition + violation + specific consequence. Other answers either generalize or imply causation.
Each of the company's three departments has at least one employee who has completed advanced safety training.
No employee works in more than one department.
The Human Resources department has the fewest employees.
Question:
If the statements above are true, which one of the following must also be true?
A. At least one employee who completed advanced safety training works in Human Resources.
B. No employee who completed advanced safety training works in Human Resources.
C. The department with the most employees has no safety-trained workers.
D. Some employees in Human Resources have not completed safety training.
E. Every employee in Human Resources has completed safety training.
✅ Correct Answer: A
Explanation:
We’re told each department, including Human Resources, has at least one employee with advanced safety training. So A must be true.
Speaker A: “Ethical decisions should be based on consequences; what matters is the results produced.”
Speaker B: “Some actions are morally wrong no matter what their consequences are; rules or duties sometimes override consequences.”
Question: The point at issue between A and B is whether:
(A) ethical rules should sometimes be overruled by positive consequences.
(B) consequences are irrelevant to moral evaluation.
(C) only the consequences matter in ethics.
(D) ethical duties exist independently of outcomes.
(E) consequences should never be ignored.
Answer: (A).
Explanation: Speaker A holds a consequentialist view: ethics judged by outcomes. Speaker B holds a deontological view: some actions are wrong even if they lead to good outcomes. They disagree over whether ethical rules or duties can be overruled by consequences. Choice (A) captures that conflict.
To reduce electricity costs, many businesses install motion-sensor lights that turn off when rooms are unoccupied. However, a study showed that such systems led to no reduction in overall energy usage. Therefore, the systems did not save businesses any money unless ______.
Question: Which of the following most logically completes the argument?
(A) The businesses used energy for other purposes that offset the savings.
(B) Energy prices increased during the study.
(C) The lights used were not energy efficient to begin with.
(D) The lights were in rooms that were rarely unoccupied.
(E) Businesses reduced electricity usage elsewhere.
✅ Answer: (A)
Explanation: The argument says no energy savings = no cost savings, unless energy usage increased elsewhere (so the savings were hidden). Only (A) makes the “unless” clause logically complete.
Students with high absence rates tend to score lower on tests.
Therefore, requiring stricter documentation for absences will improve student test scores.
The reasoning in the argument is flawed because:
A. It assumes students with absences also perform poorly in other ways.
B. It ignores the difference between excused and unexcused absences.
C. It presumes that absences are the main cause of low performance.
D. It fails to address students who attend class but don’t pay attention.
E. It overlooks the role of teachers in influencing scores.
✅ Correct Answer: C
🟨 Explanation:
The argument assumes that absences cause low test scores and that reducing absences (through stricter rules) will raise performance. But correlation ≠ causation — low scores might stem from other factors like disengagement or learning difficulties. This is a causal oversimplification flaw.
People who eat at least five servings of vegetables daily tend to live longer than those who don’t.
Therefore, if Maya eats five servings of vegetables each day, she will live longer than people who eat fewer.
Which of the following, if assumed, most helps to justify the conclusion?
A. Maya will maintain this vegetable intake for the rest of her life.
B. Maya currently eats less than five servings of vegetables per day.
C. Eating vegetables improves one’s mood and energy levels.
D. No other health factors influence how long Maya will live.
E. People who live longer tend to make better dietary choices overall.
✅ Correct Answer: A
🟨 Explanation:
To justify that Maya will live longer, we need to assume she’ll continue the behavior that correlates with longer life — eating five servings daily. That’s what answer A provides. Other answers talk about causes or correlations but don’t close the logic gap.
All of the art displayed in the museum’s new wing is from the 20th century.
None of the sculptures displayed in the new wing were created after 1950.
Some paintings displayed in the new wing were created in the 1960s.
Question:
If the statements above are true, which one of the following must also be true?
A. No sculptures in the new wing were created in the 1960s.
B. All the artwork from the 20th century was created before 1960.
C. Some of the sculptures in the new wing are not from the 20th century.
D. Some of the paintings in the new wing were created before 1950.
E. All sculptures in the museum were created after 1960.
✅ Correct Answer: A
Explanation:
No sculptures in the wing were created after 1950, so it’s impossible for any to be from the 1960s → A must be true.
Paraphrase:
Speaker A: “Artistic creativity flourishes best when artists are free from commercial constraints — when they are not pressured by deadlines or profit motives.”
Speaker B: “Some of the most innovative art has emerged precisely under tight deadlines or commercial constraints; constraints can force creativity.”
Question: They disagree about whether:
(A) all commercial pressures are harmful to artistic creativity.
(B) constraints can foster innovation in art.
(C) profit motives degrade the quality of art.
(D) deadlines alone reduce an artist’s creative output.
(E) freedom from constraints is necessary for genuine creativity.
Answer: (B).
Explanation: Speaker A claims commercial pressure (deadlines, profit motives) harms creativity. Speaker B claims that constraints (including commercial or deadlines) sometimes help innovation. The direct disagreement is whether constraints can help produce innovative art.
Critics claim that the new antidepressant is not effective because 40% of patients reported no change. But in fact, 60% of patients reported significant improvement. Therefore, the antidepressant is effective.
Question: Which of the following is an assumption the argument depends on?
(A) The 60% who improved did so because of the drug.
(B) No placebo was used in the trial.
(C) The side effects did not cause improvement.
(D) The 40% reported no worsening either.
(E) Effectiveness is judged only by self-reporting.
✅ Answer: (A)
Explanation: To say the drug is effective, the argument must assume that the improvement was caused by the drug, not something else (e.g., placebo, time, other treatment). That’s a classic causal assumption.
After the city’s public transit initiative launched, car traffic downtown dropped 20%.
At the same time, local businesses reported lower profits. Therefore, the initiative caused the decline in business revenue.
Which of the following most clearly reveals a flaw in the reasoning above?
A. It presumes that transit users don’t spend money downtown.
B. It assumes that drivers are more likely to shop than other customers.
C. It treats a coincidental relationship as if it were causal.
D. It fails to investigate whether businesses experienced a decline in foot traffic.
E. It presumes that lower profits directly reflect fewer customers.
✅ Correct Answer: C
🟨 Explanation:
The argument assumes that because two things happened at the same time, one caused the other. This is the post hoc ergo propter hoc fallacy. Profits could have fallen for many unrelated reasons (inflation, seasonal variation, economic downturn, etc.).
Critic: The museum’s plan to charge an entry fee is misguided. It claims this fee will increase revenue, but revenue is already rising due to increased donations.
Therefore, implementing a fee could actually discourage future donors.
What role does the statement “revenue is already rising due to increased donations” play in the argument?
A. It supports the idea that the museum needs more funding.
B. It undermines the assumption that a fee is necessary.
C. It offers a reason to believe the fee will succeed.
D. It restates the conclusion in different terms.
E. It contradicts the critic’s main recommendation.
✅ Correct Answer: B
🟨 Explanation:
The critic is challenging the necessity of the fee. By pointing out that revenue is already rising, they suggest that the fee isn’t needed. So this statement undermines the assumption that the fee is the only or best way to raise revenue.
All of the reptiles at the sanctuary are either snakes or lizards.
Some of the snakes were recently rescued from illegal pet trades.
None of the lizards at the sanctuary are venomous.
At least one of the reptiles at the sanctuary is venomous.
Question:
If the statements above are true, which one of the following must also be true?
A. Some venomous reptiles at the sanctuary are snakes.
B. All of the snakes at the sanctuary are venomous.
C. Some lizards at the sanctuary were rescued from illegal pet trades.
D. None of the snakes at the sanctuary are venomous.
E. All venomous reptiles at the sanctuary are lizards.
✅ Correct Answer: A
Explanation:
Since none of the lizards are venomous, but at least one reptile is, it must be a snake. So at least one snake is venomous → A must be true.