Mensa IQ Test Mensa IQ Syllogisms and Logical Arguments 8

Question 1

Premises: All P are Q. Some R are Q. Which conclusion is valid?

Accepted Answer

Nothing necessarily follows about P and R

Answer

Some P are R

Answer

All R are P

Answer

No P are R

Question 2

Argument: 'Steak has iron, spinach has iron — therefore steak and spinach taste the same.' What is wrong?

Accepted Answer

False analogy — sharing one property doesn't make things identical

Answer

Sound argument

Answer

Modus tollens

Answer

Circular reasoning

Question 3

All birds have wings. All creatures with wings can fly. Penguins are birds. Which conclusion follows?

Accepted Answer

Penguins can fly (logically, given these premises)

Answer

Penguins cannot fly

Answer

Penguins do not have wings

Answer

Birds cannot fly

Question 4

Premises: No A are B. Some C are A. Which is valid?

Accepted Answer

Some C are not B

Answer

All C are B

Answer

No C are B

Answer

All B are C

Question 5

Argument: 'I can't be wrong — I've never been wrong before.' This is which fallacy?

Accepted Answer

Appeal to personal incredulity / overconfidence bias

Answer

Slippery slope

Answer

Ad hominem

Answer

Straw man

Question 6

All mammals are vertebrates. No vertebrates are invertebrates. What about mammals and invertebrates?

Accepted Answer

No mammals are invertebrates

Answer

Some mammals are invertebrates

Answer

All invertebrates are mammals

Answer

Mammals may or may not be invertebrates

Question 7

Premises: If A then B. If B then C. If C then D. A is true. What follows?

Accepted Answer

D is true

Answer

Only B is true

Answer

Only C is true

Answer

Nothing follows