Mensa IQ Test Mensa IQ Syllogisms and Logical Arguments 7

Question 1

Premises: Some A are B. Some B are C. Which conclusion is valid?

Accepted Answer

Nothing necessarily follows

Answer

Some A are C

Answer

All A are C

Answer

No A are C

Question 2

All democracies hold elections. Country X holds elections. Can we conclude Country X is a democracy?

Accepted Answer

No — this affirms the consequent

Answer

Yes — modus ponens

Answer

Yes — definitively

Answer

No — this is a straw man

Question 3

No mammals lay eggs. Platypuses lay eggs. Therefore:

Accepted Answer

Platypuses are not mammals (given these premises)

Answer

Platypuses are mammals

Answer

Some mammals lay eggs

Answer

Eggs are not laid by vertebrates

Question 4

Argument: 'The ancient Greeks believed the Earth was flat, therefore it must have been flat then.' This is:

Accepted Answer

Appeal to tradition (false)

Answer

Sound argument

Answer

Modus ponens

Answer

Hypothetical syllogism

Question 5

All M are P. No S are M. Which conclusion is valid?

Accepted Answer

Nothing can be concluded about S and P

Answer

No S are P

Answer

All S are P

Answer

Some S are P

Question 6

If it is raining, the match is cancelled. The match is cancelled. Is there another possible reason?

Accepted Answer

Yes — cancellation could have other causes

Answer

No — only rain cancels matches

Answer

The match must be raining

Answer

This is modus tollens

Question 7

All kind people are generous. Sarah is not generous. Which is valid?

Accepted Answer

Sarah is not kind

Answer

Sarah is kind

Answer

All generous people are Sarah

Answer

Nothing follows