LLN Critical Thinking & Reasoning 1 β Questions and Answers
Question 1: If all squares are rectangles and all rectangles are parallelograms, which of the following must be true?
- All squares are parallelograms. (Correct answer)
- All parallelograms are squares.
- All squares are rectangles and parallelograms.
- All rectangles are squares.
Correct answer: All squares are parallelograms.
This question relies on the transitive property of logical statements. If all squares are rectangles, and all rectangles are parallelograms, then it logically follows that all squares must also possess the properties of parallelograms. This chain of inclusion means squares are a subset of rectangles, which are a subset of parallelograms.
Question 2: If A is greater than B, and B is greater than C, which of the following must be true?
- A is less than C.
- A is greater than C. (Correct answer)
- B is equal to C.
- A is equal to B.
Correct answer: A is greater than C.
This question illustrates the transitive property of inequalities. If A is greater than B, and B is in turn greater than C, it logically follows that A must also be greater than C. This establishes a clear hierarchical relationship among the three quantities.
Question 3: Which of the following conclusions can be made from the statement: 'All birds have feathers'?
- All animals have feathers.
- Some birds may not have feathers.
- All birds have feathers, but not all animals do. (Correct answer)
- All animals are birds.
Correct answer: All birds have feathers, but not all animals do.
The statement 'All birds have feathers' defines a universal characteristic of birds. While it confirms that feathers are present on all birds, it does not imply that feathers are exclusive to birds or that every animal possesses them. Therefore, the most accurate conclusion is that this trait is specific to birds within the broader animal kingdom, but not all animals share it.
Question 4: If all mammals are warm-blooded and all warm-blooded animals have fur, which of the following is true?
- All mammals have fur. (Correct answer)
- Some mammals may not have fur.
- All warm-blooded animals are mammals.
- All animals with fur are warm-blooded.
Correct answer: All mammals have fur.
This is an example of a syllogism, a form of deductive reasoning. If all mammals fall into the category of warm-blooded animals, and all warm-blooded animals possess fur, then it logically follows that all mammals must also possess fur. The characteristic of having fur is directly extended to mammals through the intermediate classification of being warm-blooded.
Question 5: Which of the following is an example of a valid conclusion based on the following premise? 'If it rains tomorrow, we will go to the park.'
- If it does not rain tomorrow, we will not go to the park.
- We will go to the park only if it rains tomorrow.
- If we go to the park, it must rain tomorrow.
- If it rains tomorrow, we will go to the park. (Correct answer)
Correct answer: If it rains tomorrow, we will go to the park.
A valid conclusion based on a premise is often the premise itself, as it is inherently true if the premise is true. The statement 'If it rains tomorrow, we will go to the park' is a conditional statement. The correct answer simply reiterates this original premise, which is always a logically sound conclusion.
Question 6: Which of the following statements can be logically inferred from the following premise? 'No cats are reptiles, and all reptiles are cold-blooded.'
- Some cats are cold-blooded.
- All cats are warm-blooded. (Correct answer)
- All reptiles are cats.
- Some reptiles are cats.
Correct answer: All cats are warm-blooded.
The premise 'No cats are reptiles' establishes that cats and reptiles are distinct categories. Since 'all reptiles are cold-blooded,' and cats are not reptiles, it implies that cats do not share the characteristic of being cold-blooded in the same way reptiles do. In the context of common animal classifications, if an animal is not cold-blooded, it is typically considered warm-blooded, leading to the inference that all cats are warm-blooded.
Question 7: If all teachers are knowledgeable and John is a teacher, which of the following is true?
- John is not knowledgeable.
- John is knowledgeable. (Correct answer)
- John may or may not be knowledgeable.
- John is not a teacher.
Correct answer: John is knowledgeable.
This is a straightforward application of deductive reasoning. The first premise states a general rule: every individual in the 'teacher' group is 'knowledgeable.' The second premise identifies John as a member of the 'teacher' group. Therefore, it logically and necessarily follows that John must also possess the characteristic of being knowledgeable.
Question 8: Which of the following is an example of a logical fallacy?
- If it rains, the ground will get wet. Itβs raining, so the ground is wet.
- If I study hard, I will pass the exam. I studied hard, so I will pass.
- If I am hungry, I will eat. I am eating, so I am hungry.
- If I see a bird, it must be a sparrow.
This statement commits the logical fallacy known as affirming the consequent. The premise 'If I am hungry, I will eat' (If P, then Q) does not mean that 'If I am eating, then I must be hungry' (If Q, then P). There can be other reasons for eating besides hunger, making the conclusion invalid.
Question 9: Which of the following statements is a valid argument?
- If I study, I will pass the exam. I did not study, so I will not pass.
- If I go to the park, I will bring an umbrella. I went to the park, so I brought an umbrella. (Correct answer)
- If it rains, I will stay home. I stayed home, so it must have rained.
- If I am hungry, I will eat. I am eating, so I am hungry.
Correct answer: If I go to the park, I will bring an umbrella. I went to the park, so I brought an umbrella.
This is a valid argument form called Modus Ponens. The first statement sets up a conditional: 'If P (go to the park), then Q (bring an umbrella).' The second statement affirms the antecedent (P occurred). Therefore, the conclusion that the consequent (Q occurred) is logically sound and must be true.
If all squares are rectangles and all rectangles are parallelograms, which of the following must be true?