N5 Validity (S4)

P1: All girls are hilarious.

P2: Nobody who is hilarious has hair.

C: No girls have hair.

• Valid

• Invalid

Answer explanation

All A are B;

No B are C;

Therefore, No A are C.

P1: All teachers work too much.

P2: Nobody who works too much enjoys their job.

C: No teacher enjoys their job.

• Invalid

• Valid

Answer explanation

All A are B;

No B are C;

Therefore, No A are C.

P1: All people who gossip make people feel bad.

P2: Nobody who makes people feel bad has ever been funny.

C: Nobody who gossips has ever been funny.

• Valid

• Invalid

Answer explanation

All A are B;

No B are C;

Therefore, No A are C.

P1: All pigs are intelligent creatures.

P2: No intelligent creatures should be eaten.

C: No pigs should be eaten.

• Invalid

• Valid

Answer explanation

All A are B;

No B are C;

Therefore, No A are C.

P1: All humans are born.

P2: Some who are born will die.

C: Some humans will die.

• Invalid

• Valid

Answer explanation

All A are B;

Some B are C;

Therefore, some A are C.

P1: All people over 90 live in England.

P2: Some people who live in England hate marmite.

C: Some people over 90 hate marmite.

• Valid

• Invalid

Answer explanation

All A are B;

Some B are C;

Therefore, some A are C.

P1: All philosophy students have to study logic.

P2: Some students who study logic will study philosophy at university.

C: Some philosophy students will study philosophy at university.

• Valid

• Invalid

Answer explanation

All A are B;

Some B are C;

Therefore, some A are C.

P1: All vegan food is healthy food.

P2: Some healthy food is really tasty.

C: Some vegan food is really tasty.

• Invalid

• Valid

Answer explanation

All A are B;

Some B are C;

Therefore, some A are C.

P1: All kittens are adorable.

P2: Ebba is adorable.

C: Ebba is a kitten.

• Valid

• Invalid

Answer explanation

All A’s are F;

X is F;

Therefore, X is an A.

P1: All Watson’s kids have good teachers.

P2: Michael has good teachers.

C: Michael is a Watson’s kid.

• Valid

• Invalid

Answer explanation

All A’s are F;

X is F;

Therefore, X is an A.