Civil Service Verbal Reasoning Test Critical Reasoning and Logical Inference

Question 1

All mammals are warm-blooded. Dolphins are mammals. Which conclusion MUST be true?

Accepted Answer

Dolphins are warm-blooded

Answer

This is a valid syllogism. If all mammals are warm-blooded and dolphins are mammals, then dolphins must be warm-blooded.

Question 2

No students who failed the exam passed the course. James failed the exam. Which conclusion MUST be true?

Accepted Answer

James did not pass the course

Answer

The rule states no exam-failers passed the course. James failed the exam, so he must not have passed the course. This follows logically.

Question 3

If it rains, the match is cancelled. The match was not cancelled. Which conclusion is VALID?

Accepted Answer

It did not rain

Answer

This uses the logical form of contrapositive: if P then Q; not Q, therefore not P. If rain causes cancellation and there was no cancellation, it did not rain.

Question 4

All the files in folder A are marked confidential. This file is not marked confidential. Which MUST be true?

Accepted Answer

This file is not in folder A

Answer

If all files in folder A are confidential, and this file is not confidential, it cannot be in folder A. The contrapositive is valid.

Question 5

A survey found that people who drink coffee daily score higher on alertness tests. The survey concludes coffee improves alertness. Which WEAKENS this conclusion?

Accepted Answer

Alert people may be more likely to drink coffee, not the other way round

Answer

The conclusion assumes coffee causes alertness, but the relationship could be reversed — alert people may choose to drink coffee. This is the reverse causation flaw.

Civil Service Verbal Reasoning Practice Test

Civil Service Verbal Reasoning Practice Test

Civil Service Verbal Reasoning Test Critical Reasoning and Logical Inference