All frogs are animals. Therefore, all frogs are cats. Therefore, it is invalid. Unsound, because it's invalid. No cats like seafood.
All seafood is cheap.
All cats like expensive food. Even if we pretend that the premises are true, the conclusion could be false. Unsound, because it's invalid. If you are still confused after doing this exercise, try the supplementary exercises . Click here to return to the course home page .