Q. All dogs are animals. Some animals are not pets. Therefore, some dogs are not pets. Is this conclusion valid?
A.
Yes
B.
No
C.
Only if all animals are dogs
D.
Only if some pets are not animals
Solution
The conclusion is not valid because while all dogs are animals, it does not imply that some dogs are not pets since all dogs could potentially be pets.
Q. All squares are rectangles. Some rectangles are not squares. Therefore, some squares are not rectangles. Is this conclusion valid?
A.
Yes
B.
No
C.
Only if all rectangles are squares
D.
Only if some rectangles are not squares
Solution
The conclusion is not valid because all squares are indeed rectangles, and the fact that some rectangles are not squares does not affect the status of squares as rectangles.
Q. No birds are fish. All fish are animals. Therefore, no birds are animals. Is this conclusion valid?
A.
Yes
B.
No
C.
Only if all animals are birds
D.
Only if some birds are fish
Solution
The conclusion is not valid because while no birds are fish, it does not imply that no birds are animals since birds can belong to a different category of animals.
Q. Some cars are electric. All electric vehicles are eco-friendly. Therefore, some cars are eco-friendly. Is this conclusion valid?
A.
Yes
B.
No
C.
Only if all cars are electric
D.
Only if some eco-friendly vehicles are not cars
Solution
The conclusion is valid because if some cars are electric and all electric vehicles are eco-friendly, it follows that those cars that are electric must also be eco-friendly.
