What is logical reasoning?

Logical reasoning is the ability to reach conclusions that must follow from a set of given facts or rules, by eliminating every possibility the clues rule out. In tests it appears as ordering and matching puzzles, if-then rules, and truth-teller and liar problems.

It measures deductive reasoning: working strictly from the information given rather than from assumptions. Employer tests use it for analytical, legal, technical and management roles.

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

Format: Clue sets with a question and 4–5 options
Puzzle families: Ordering, matching, if-then, truth & lies
Typical employer test: 15–25 items in 20–30 minutes
Measures: Deduction, systematic elimination, rule following
This test: 10 puzzles, 15 minutes, free

Four puzzle families

Employer logic tests mix these four. Each needs a slightly different way of writing things down.

OrderingWho finished where, which floor, which day. Clues compare positions.Write it as: a line of slots, filled left to right

Pia is ahead of Raj. Raj is ahead of Sol. Who's last?Pia → Raj → Sol: Sol

MatchingEach person gets exactly one item. Clues mostly say who doesn't have what.Write it as: a grid of ✗ and ✓

Tom, Una and Vic own a van, a bike and a car. Tom doesn't own the van. Una owns the bike. Who owns the van?Una=bike, Tom≠van → Vic=van

If-thenRules of the form 'if A then B', and one extra fact. Only two moves are safe.Write it as: arrows: A → B

If the shop's open, the sign is lit. The sign isn't lit.¬lit → ¬open: it's closed

Truth & liesSpeakers who always lie or always tell the truth. Assume one case and look for a contradiction.Write it as: a T/L row per speaker, then test

A says 'I am a liar'. Possible?T can't say it, L can't either → no such A

THE MOST FAMOUS LOGIC PUZZLE

The four-card problem

Peter Wason's 1966 task. Each card has a letter on one side and a number on the other. In the abstract version, most people get it wrong. Switch to the bar version and watch it become easy, though the logic is identical.

~10%solve the abstract version [1]

~75%solve the drinking-age version [2]

Rule:If a card has a vowel on one side, it has an even number on the other.Which cards must you turn over to check whether the rule is broken? Pick only the ones you need.

IF-THEN RULES

Two moves work. Two only look like they do.

Given "if it rains, the street is wet", there are four ways to reason from one extra fact. Pick each to see whether it holds.

RULEIf it rains, the street is wet.

FACTThe street is wet.

SO…It rained.

Affirming the consequent · invalidInvalid: a burst pipe or a street cleaner also makes it wet.

Shorthand that saves minutes

Never hold a clue in your head. Turn each sentence into a mark on paper the moment you read it.

A is ahead of BA … BDots mean 'somewhere before', not 'directly'.

A is directly before BABGlue them into one block; it moves as a unit.

A is not next to BA ✗ BMark the banned pairs on your slot line.

If A, then BA → BOnly forwards from A, or backwards from not-B.

Not A¬AKeep negatives visible: they're half of most matching clues.

Exactly one is trueΣ = 1Test each case and count the true statements.

Take the test

10 puzzles · 15 minutes · paper and pen recommended

Ordering3 puzzlesMatching2 puzzlesIf-then3 puzzlesTruth & lies2 puzzles

Puzzle 1 of 10Ordering

00:00

1A finished before B.2C finished after D but before A.3E finished last.

Who finished first?

0/10Use the shorthand above, then try again.Weakest: ordering (0/3) · 29854925:43

Ordering0/3Matching0/2If-then0/3Truth & lies0/2

Puzzle 1 · OrderingAnswer: D · you chose nothingChain the clues: D → C → A → B, with E last. D is first.

Puzzle 2 · OrderingAnswer: Yellow · you chose nothingGreen takes 4. Yellow must sit right before Blue with Red further left, so only Red, Yellow, Blue fits.

Puzzle 3 · MatchingAnswer: Cara · you chose nothingBen has the fish, Ana can't have the dog, so Ana has the cat and Cara the dog.

Puzzle 4 · MatchingAnswer: Dev · you chose nothingEli must be Tuesday. Fay is after Dev, so Dev is Monday and Fay Wednesday.

Puzzle 5 · If-thenAnswer: The alarm is not set · you chose nothingDenying the result (modus tollens): if the alarm were set the light would be red, so it isn't set. 'Green' is never mentioned.

Puzzle 6 · If-thenAnswer: Nothing about its weight follows · you chose nothingAffirming the result is a trap: light parcels could go by van too. The rule only says what heavy parcels do.

Puzzle 7 · If-thenAnswer: Sam stays home · you chose nothingFollow the chain forward: Mia goes → Leo goes → Sam stays home.

Puzzle 8 · Truth & liesAnswer: A liar, B truth-teller · you chose nothingA can't be truthful (a truth-teller wouldn't call himself a liar). So A lies, the statement is false, and B must be truthful.

Puzzle 9 · Truth & liesAnswer: Door 2 · you chose nothingTest each door. Only the prize behind door 2 makes exactly one sign (door 3's) true.

Puzzle 10 · OrderingAnswer: Nia is taller than Max · you chose nothingNia > Kai > Lu > Max, so Nia is taller than Max.

How to solve a logic puzzle

1Write each clue as notationTurn every sentence into a mark: A … B, AB, A → B, ¬A.
2Place the certaintiesFill in anything a clue fixes outright before anything else.
3EliminateUse the negative clues to cross off what can't be true.
4Test the remaining casesIf two possibilities are left, assume one and look for a contradiction.

Keep going

Verbal syllogismsDeduction with 'all', 'some' and 'no'.Open

Abstract reasoningFind rules in shapes instead of sentences.Open

Verbal reasoningTrue, false or cannot say on real passages.Open

References

Wason, P. C. (1966). Reasoning. In B. M. Foss (Ed.), New Horizons in Psychology (pp. 135–151). Harmondsworth: Penguin.
Griggs, R. A., & Cox, J. R. (1982). The elusive thematic-materials effect in Wason's selection task. British Journal of Psychology, 73(3), 407–420.
Cosmides, L. (1989). The logic of social exchange: Has natural selection shaped how humans reason? Cognition, 31(3), 187–276.
Johnson-Laird, P. N. (2006). How We Reason. Oxford University Press.

Every clue rules something out.