Critical Thinking & Reasoning Flashcards

If all squares are rectangles and all rectangles are parallelograms, which of the following must be true?

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.

If A is greater than B, and B is greater than C, which of the following must be true?

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.

Which of the following conclusions can be made from the statement: 'All birds have feathers'?

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.

If all mammals are warm-blooded and all warm-blooded animals have fur, which of the following is true?

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.

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.'

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.

Which of the following statements can be logically inferred from the following premise? 'No cats are reptiles, and all reptiles are cold-blooded.'

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.

If all teachers are knowledgeable and John is a teacher, which of the following is true?

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.

Which of the following statements is a valid argument?

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.