Practice Deductive Reasoning Test

What is deductive reasoning?

Deductive reasoning is drawing conclusions that are guaranteed to be true if the starting statements (premises) are true.

It runs from general rules to specific cases, the opposite of inductive reasoning. Tests ask you to judge whether a statement must be true, could be true or cannot be true given the premises, while ignoring what you know about the real world.

By What's Your IQ · Published 3 Oct 2026 · Updated 3 Oct 2026

Format: Premises, then a statement or set of conclusions
Answer types: Must / could / cannot be true, or "which must follow?"
Typical employer test: 20–30 items in 20–30 minutes
Measures: Conditional logic, quantifiers, careful reading
This test: 12 items, 12 minutes, free, explained answers

Sort five statements

Read the three rules once, then sort each statement. "Could" means the rules allow it but don't force it.

1All managers attend the briefing.

2Some people at the briefing work remotely.

3No interns attend the briefing.

Some managers work remotely.

No manager is an intern.

An intern attends the briefing.

Some remote workers are not interns.

Everyone at the briefing is a manager.

Translate the tricky words

Rewrite each premise into one of these forms before you judge anything. Most wrong answers start with a mistranslation.

THE TEST SAYSMEANSTHE ONLY THING IT RULES OUT

A only if BIf A → BA happening without B. It doesn't say B causes A.

A unless BIf not B → ANeither A nor B happening. Both together is fine.

Not all X are YSome X are not YEvery X being Y. It doesn't say none are.

No X except YIf X → YAn X that isn't Y.

A or BAt least oneNeither. Both is allowed unless it says “but not both”.

Only X are YIf Y → XA Y that isn't X. Note the reversal from “all X are Y”.

THE NEGATION TRAP

The opposite of "all" isn't "none"

"Cannot be true" questions often hinge on what a statement's true opposite is. Here are the four you'll meet most.

"All the trains were on time."

None of the trains were on time.

At least one train was late.

"Some candidates passed."

Some candidates failed.

No candidate passed.

"If it rains, we stay in."

If it doesn't rain, we go out.

It rains and we don't stay in.

"Ali and Bo both came."

Neither Ali nor Bo came.

At least one of Ali and Bo didn't come.

Take the test

12 items · 12 minutes · judge only from the premises

Must / could / cannot10 items, three options eachWhich must follow2 items, four conclusions

Item 1 of 12All-statements

00:00

PREMISES

All pilots are trained.Sam is a pilot.

"Sam is trained."

0/12Translate each premise first, then try again.Weakest: all-statements (0/4) · 29854919:33

All-statements0/4If-then0/3Some-statements0/2Either-or0/1Which must follow0/2

Item 1 · All-statementsAnswer: Must be true · you chose nothingAll pilots are trained and Sam is one, so it's forced.

Item 2 · All-statementsAnswer: Could be true · you chose nothingThe rule says nothing about trained people who aren't pilots. Kim might or might not be one.

Item 3 · All-statementsAnswer: Cannot be true · you chose nothingNothing can be both. Rex is a dog, so he can't be a cat.

Item 4 · If-thenAnswer: Cannot be true · you chose nothingA down server would make the site offline. It's online, so the server isn't down.

Item 5 · If-thenAnswer: Must be true · you chose nothing“A only if B” means if A then B. Lea entered, so she has a badge.

Item 6 · If-thenAnswer: Must be true · you chose nothing“Unless” means: if it's not a holiday, the shop opens. It didn't open, so it must be a holiday.

Item 7 · Some-statementsAnswer: Must be true · you chose nothingThe engineers who are managers are on the board, so at least some engineers are.

Item 8 · Some-statementsAnswer: Could be true · you chose nothing“Not all” means at least one wasn't checked. Some might have been, or none.

Item 9 · Either-orAnswer: Could be true · you chose nothingWith “or both” allowed, Ana going tells you nothing about Ben.

Item 10 · All-statementsAnswer: Cannot be true · you chose nothingIf Raj had done it, it would be approved. It wasn't, so he didn't.

Item 11 · Which must followAnswer: Maya doesn't use Lotus. · you chose nothingMaya is an analyst, so she uses Excel, so she doesn't use Lotus. The rules don't say she uses nothing else.

Item 12 · Which must followAnswer: It did not snow. · you chose nothingWork backwards: not cancelled → school didn't close → it didn't snow. Nothing says the match was played at all.

Keep going

Logical reasoningOrdering, matching and truth-teller puzzles.Open

Verbal syllogismsAll, some and no arguments in depth.Open

Inductive reasoningThe other direction: from examples to rules.Open

References

Johnson-Laird, P. N. (1983). Mental Models: Towards a Cognitive Science of Language, Inference, and Consciousness. Cambridge University Press.
Rips, L. J. (1994). The Psychology of Proof: Deductive Reasoning in Human Thinking. MIT Press.
Evans, J. St. B. T. (2002). Logic and human reasoning: An assessment of the deduction paradigm. Psychological Bulletin, 128(6), 978–996.