Deductive Reasoning Quiz

In deductive reasoning, the conclusion is probabilistic and may not be true even if the premises are true.

• TRUE

• FALSE

Answer explanation

In deductive reasoning, the resulting conclusion is always true if the premises are true.

Premises are the pieces of evidence or information that are put forward to support or justify a specific conclusion or claim.

• TRUE

• FALSE

Major premise is the specific statement or evidence that relates directly to the particular case or situation being discussed.

• TRUE

• FALSE

(1) All doctors are skilled professionals.

(2) Sarah is a skilled professional.

(3) Therefore, Sarah is a doctor.

Which one is the minor premise?

• 1

• 2

• 3

In a valid syllogism, if both the major and minor premises are true, what can be said about the conclusion?

• If the major premise is true but minor premise is false, the conclusion must also be true.

• If one of the major or minor premises of a syllogism are true, the conclusion must also be true.

• If both the major and minor premises of a syllogism are true, the conclusion must also be true.

• If the major premise is false but minor premise is true, the conclusion must also be true.

VALID OR NOT:

Major Premise: All cats have tails.

Minor Premise: Max has a tail.

Conclusion: Therefore, Max is a cat.

• VALID

• INVALID

Answer explanation

This is an invalid inference. While the conclusion could be true, it doesn't logically follow from the premises. Max could be a dog or some other animal with a tail.

VALID OR NOT:

Major Premise: No birds are mammals.

Minor Premise: Dogs are mammals.

Conclusion: Therefore, dogs are not birds.

• VALID

• INVALID

Answer explanation

This is an invalid inference. While the conclusion is true, it doesn't follow logically from the premises. The premises don't provide enough information to draw this conclusion.

VALID OR NOT:

Major Premise: All students study mathematics.

Minor Premise: Lisa studies mathematics.

Conclusion: Therefore, Lisa is a student.

• VALID

• INVALID

Answer explanation

This is an invalid inference. The conclusion could be true, but it doesn't logically follow from the premises. Lisa could be a mathematics teacher or researcher, not necessarily a student.

What is the conclusion?

Major Premise: No mammals have feathers.

Minor Premise: Penguins have feathers.

• Therefore, penguins are not mammals.

• Therefore, some mammals are penguin.

• No conclusion can be made.

• Therefore, some penguins are mammals.

Modus Tollens is a Latin term that means "the way that affirms by affirming."

• TRUE

• FALSE