GCAT Critical Thinking and Problem Solving 1 — Questions and Answers
Question 1: Which of the following best describes a valid argument?
- An argument where the conclusion is true
- An argument where if the premises are true, the conclusion must be true (Correct answer)
- An argument that uses many supporting examples
- An argument that appeals to the audience's emotions
Correct answer: An argument where if the premises are true, the conclusion must be true
A valid argument is one where the conclusion necessarily follows from the premises, regardless of whether the premises are actually true.
Question 2: If 'all roses are flowers' and 'some flowers fade quickly,' which conclusion is necessarily true?
- All roses fade quickly
- Some roses are flowers (Correct answer)
- No roses fade quickly
- All flowers are roses
Correct answer: Some roses are flowers
Since all roses are flowers, the set of roses is a subset of flowers, so it is necessarily true that some roses are flowers.
Question 3: A manager notices sales increased after changing the office decor and concludes the decor caused the increase. What logical error is being made?
- False dichotomy
- Post hoc ergo propter hoc — confusing correlation with causation (Correct answer)
- Circular reasoning
- Appeal to authority
Correct answer: Post hoc ergo propter hoc — confusing correlation with causation
Assuming that because one event followed another the first caused the second is the post hoc ergo propter hoc fallacy.
Question 4: Which of the following is an example of deductive reasoning?
- Every swan I have seen is white, so all swans must be white
- All mammals are warm-blooded; dogs are mammals; therefore dogs are warm-blooded (Correct answer)
- It rained every Monday last month, so it will rain next Monday
- My experiment worked three times, so it will always work
Correct answer: All mammals are warm-blooded; dogs are mammals; therefore dogs are warm-blooded
Deductive reasoning moves from general premises to a specific conclusion that must be true if the premises are true.
Question 5: Which research design best controls for bias when testing whether a new drug is effective?
- Give the drug to all willing participants and ask if they feel better
- Give the drug to patients who request it and compare them to those who do not
- Randomly assign participants to drug or placebo groups with neither group knowing which they received (Correct answer)
- Give the drug to the sickest patients and compare their recovery to healthy people
Correct answer: Randomly assign participants to drug or placebo groups with neither group knowing which they received
A double-blind randomized controlled trial eliminates selection bias and placebo effects, providing the most reliable causal evidence.
Question 6: Given 'No athletes are lazy' and 'Some students are athletes,' which conclusion necessarily follows?
- Some students are not lazy (Correct answer)
- All students are not lazy
- No students are athletes
- All athletes are students
Correct answer: Some students are not lazy
Since some students are athletes and no athletes are lazy, those student-athletes must not be lazy, so some students are not lazy.
Question 7: Which of the following MOST strengthens the argument: 'We should invest in renewable energy because it reduces carbon emissions'?
- Renewable energy is currently more expensive than fossil fuels
- Carbon emissions are a leading cause of climate change (Correct answer)
- Some renewable energy sources can be unreliable
- Many countries still rely heavily on coal
Correct answer: Carbon emissions are a leading cause of climate change
Showing that carbon emissions cause serious harm (climate change) strengthens the argument by making their reduction more urgent and valuable.
GCAT Critical Thinking and Problem Solving 1
Which of the following best describes a valid argument?