Valid & Invalid Arguments Quiz

Some law textbooks are too heavy to carry into class. All things that are too heavy to carry into class are impractical. Thus, some law textbooks are impractical.

• Invalid

• Valid

Jonathan weighs 200 lbs.

Doris weighs 25 percent less than Jonathan.

So, Doris weighs 150lbs.

• Invalid

• Valid

Either Colonel Mustard or Miss Scarlet is the culprit.

Miss Scarlet is not the culprit.

Hence, Colonel Mustard is the culprit.

• Invalid

• Valid

If the patient has malaria, then a blood test will indicate that his blood harbors at least one of these parasites: P. ovale and P. malaria.

Blood test indicates that the patient harbors none of these parasites.

Therefore the patient does not have malaria.

• Invalid

• Valid

If I move my knight, Christian will take my knight.

If I move my queen, Christian will take my knight.

Therefore, if I move my knight, Christian will take my queen.

• Invalid

• Valid

Some bodies of water are polluted with chemical waste. All North American rivers are polluted with chemical waste. Hence, some bodies of water are North American rivers.

• Invalid

• Valid

Either Stich is an alien or Stich is a monster.

Stich is not an alien, therefore it is a monster.

• Invalid

• Valid

All wedding invitation cards are creatively designed. All wedding reception arrangements are creatively designed. So, all wedding invitation cards are wedding reception arrangements.

• Invalid

• Valid

No person with conscience is a thief. All convicted criminals are thieves. Therefore, no person with a conscience is a convicted criminal.

• Invalid

• Valid

Only people who hold stock in the company may vote, so Mr. Handsome must not hold any stock in the company, because I know he was not allowed to vote.

• Invalid

• Valid