Mensa IQ Test Mensa IQ Syllogisms and Logical Arguments 6

Question 1

Premises: No fish are mammals. Dolphins are mammals. Which MUST be true?

Accepted Answer

Dolphins are not fish

Answer

Dolphin ∈ mammals; no mammal is a fish → dolphin is not a fish.

Question 2

Argument: 'This medicine must work — my grandfather took it and lived to 95.' This commits which fallacy?

Accepted Answer

Anecdotal evidence (hasty generalisation)

Answer

Concluding a universal rule from a single personal story is a hasty generalisation / anecdotal fallacy.

Question 3

Some politicians are honest. All honest people are trustworthy. Which is valid?

Accepted Answer

Some politicians are trustworthy

Answer

Darii: some Pol are Honest; All Honest→Trustworthy → some Pol are Trustworthy.

Question 4

Argument: 'Either you're with us or you're against us.' What fallacy does this commit?

Accepted Answer

False dilemma (false dichotomy)

Answer

Presenting only two options when more exist is a false dilemma / false dichotomy.

Question 5

All S are M. All M are P. Some P are Q. Which conclusion is VALID?

Accepted Answer

All S are P

Answer

The first two premises give All S→P (Barbara); 'some P are Q' does not extend to S without more info.

Mensa Practice Test Practice Test