Constraint puzzles solved by ticking and crossing a grid. Each one gives you a small cast, a set of attributes, and clues that never state the whole answer — so you close the board by elimination, negative inference, and, at the top of the ladder, a hypothesis you deliberately break.
What this category trains
Constraint tracking
Systematic elimination
Negative inference
Grid notation
25 puzzles · about 70 minutes end to end, as a guide only · untimed
The ladder
The puzzles below run in difficulty order, easiest first. Each one checks on its own and shows its explanation straight away, so you get the method for one rung before you attempt the next.
Work through the ladder in order — the early puzzles teach the notation the later ones assume. Sketch the grid, tick a cell when a clue confirms a pairing, and cross the rest of that cell's row and column straight away; most of the work in a logic grid is done by the crosses, not the ticks. Nothing here is timed, and checking an answer shows you the method, so read the explanation even when you were right.
1. Two at the counter
Difficulty 1 of 5 · Warm-up
Iris and Owen each collect one drink from the counter. Which pairing satisfies both clues?
Two colleagues, two drinks, one drink each.
Row
Tea
Coffee
Iris
blank
blank
Owen
blank
blank
Clues
Iris and Owen order different drinks.
Iris does not order the coffee.
Show a hint
Start from the clue that rules something out. With only two drinks on the board, it settles everything.
2. Repainting the lane
Difficulty 1 of 5 · Warm-up
Two houses on the same lane are repainted, one in green and one in cream. Which pairing fits the clues?
Two houses, two colours, one colour each.
Row
Green
Cream
House 4
blank
blank
House 6
blank
blank
Clues
One house is painted green and the other is painted cream.
House 6 is painted green.
Show a hint
One clue fills a cell on its own. Place that tick first, then see what it removes from the rest of the grid.
3. A two-runner finish
Difficulty 1 of 5 · Warm-up
Two runners finish a short race. Using the clues, which pairing of runners to places is correct?
Two runners, two finishing places.
Row
First
Second
Priya
blank
blank
Ravi
blank
blank
Clues
Only two runners finished, and they took first and second place.
Ravi crossed the line before Priya.
Show a hint
Turn the comparison into a plain ordering — who is ahead of whom — before you touch the grid.
4. Two boxes on the shelf
Difficulty 1 of 5 · Warm-up
A striped box and a plain box sit on a shelf. One holds a ribbon and the other holds buttons. Which pairing is correct?
Two boxes, two items, one item each.
Row
Ribbon
Buttons
Striped box
blank
blank
Plain box
blank
blank
Clues
Each box holds exactly one of the two items.
The plain box does not hold the ribbon.
Show a hint
Rewrite the negative clue as a positive statement about the other box before you fill anything in.
5. Covering the two shifts
Difficulty 1 of 5 · Warm-up
A shop runs an early shift starting at 7am and a late shift starting at 2pm. Hana and Marek cover one shift each. Which rota fits the clues?
Two shifts, two staff, one shift each.
Row
Early shift (7am)
Late shift (2pm)
Hana
blank
blank
Marek
blank
blank
Clues
Each shift is covered by exactly one person, and nobody covers both.
Hana is unable to start work before midday.
Marek is happy to take whichever shift is left.
Show a hint
Convert the sentence about when Hana can start into a cross in one cell, then read the grid.
6. Three friends, three fruits
Difficulty 2 of 5 · Straightforward
Bea, Callum and Dilan each take one piece of fruit from a bowl holding an apple, a pear and a plum. Which set of pairings is correct?
Three friends, three fruits, one fruit each.
Row
Apple
Pear
Plum
Bea
blank
blank
blank
Callum
blank
blank
blank
Dilan
blank
blank
blank
Clues
Each friend takes exactly one fruit, and no two friends take the same fruit.
Bea takes the pear.
Dilan takes the apple.
Show a hint
Two of the three fruits are handed out directly. Count what is left rather than reasoning about it.
7. Three vehicles, three colours
Difficulty 2 of 5 · Straightforward
A hire firm keeps a hatchback, an estate and a van, each a different colour: silver, navy or red. Which set of pairings is correct?
Three vehicles, three colours, one colour each.
Row
Silver
Navy
Red
Hatchback
blank
blank
blank
Estate
blank
blank
blank
Van
blank
blank
blank
Clues
Each vehicle is a different colour.
The van is red.
The hatchback is not silver.
Show a hint
Place the vehicle whose colour is stated outright, then re-read the exclusion against what remains.
8. Three deliveries, three days
Difficulty 2 of 5 · Straightforward
Books, plants and tiles are delivered to a workshop on Monday, Tuesday and Wednesday, one delivery a day. Which set of pairings is correct?
Three deliveries, three days, one delivery a day.
Row
Monday
Tuesday
Wednesday
Books
blank
blank
blank
Plants
blank
blank
blank
Tiles
blank
blank
blank
Clues
The three deliveries arrive on three different days.
The plants arrive on Tuesday.
The tiles arrive earlier in the week than the books.
Show a hint
Fix the delivery whose day is stated, then apply the ordering clue only to the days still open.
9. Three pets, three owners
Difficulty 2 of 5 · Straightforward
Eve, Femi and Grace each own one of a cat, a rabbit and a parrot. Every clue below is a denial. Which set of pairings is correct?
Three owners, three pets, one pet each.
Row
Cat
Rabbit
Parrot
Eve
blank
blank
blank
Femi
blank
blank
blank
Grace
blank
blank
blank
Clues
Each person owns exactly one pet, and each pet has exactly one owner.
Eve does not own the parrot.
Grace does not own the parrot.
Eve does not own the rabbit.
Show a hint
Two clues talk about the same pet. Read down that column and count how many owners are ruled out.
10. Desks on three floors
Difficulty 2 of 5 · Straightforward
Ines, Jonah and Kemi have desks on the first, second and third floors of the same building, one desk to a floor. Which set of pairings is correct?
Three people, three floors, one desk on each floor.
Row
First floor
Second floor
Third floor
Ines
blank
blank
blank
Jonah
blank
blank
blank
Kemi
blank
blank
blank
Clues
Each person's desk is on a different floor.
Jonah's desk is on the second floor.
Kemi's desk is higher up than Ines's desk.
Show a hint
Place the desk whose floor is stated first; the comparison then has only two floors to sort out.
11. Three teams, three scores
Difficulty 2 of 5 · Straightforward
The Larks, the Otters and the Swifts scored 12, 18 and 24 points in a quiz, in some order. Which set of pairings is correct?
Three teams, three scores, one score each.
Row
12 points
18 points
24 points
Larks
blank
blank
blank
Otters
blank
blank
blank
Swifts
blank
blank
blank
Clues
The three teams scored 12, 18 and 24 points, with no two teams on the same score.
The Otters scored the most points of the three.
The Larks did not score 18.
Show a hint
Superlatives name a single cell. Work out what scoring the most can only mean before reading on.
12. Subjects and study days
Difficulty 3 of 5 · Tricky
Amara, Bo and Cleo each study one subject and each attend on one day. Which subject does Bo study, and on which day does Bo attend?
Three students, each with one subject and one study day.
Row
Subject
Day
Amara
blank
blank
Bo
blank
blank
Cleo
blank
blank
Clues
The subjects are geology, statistics and poetry; the days are Monday, Wednesday and Friday. No subject and no day is shared.
Amara studies statistics.
Bo does not study poetry.
Cleo attends on Monday.
Amara does not attend on Friday.
Show a hint
No clue here links a subject to a day. Solve the two attributes as separate grids, then read them together.
13. Three shops, three streets
Difficulty 3 of 5 · Tricky
Dara, Esme and Frank each run one shop selling one product on one street. What does Dara sell, and on which street does that shop stand?
Three shopkeepers, each with one product and one street.
Row
Product
Street
Dara
blank
blank
Esme
blank
blank
Frank
blank
blank
Clues
The products are candles, cheese and cameras; the streets are Bridge Street, Mill Street and Quay Street. No product and no street is shared.
Esme's shop sells cheese.
The camera shop is not on Mill Street.
Dara's shop is on Mill Street.
Frank's shop is not on Bridge Street.
Show a hint
One clue crosses out a product-and-street pairing. Work out which shopkeeper stands on that street.
14. Players and their towns
Difficulty 3 of 5 · Tricky
Rosa, Sami and Tomas each play one instrument and each live in one town. Which instrument does Sami play, and in which town does Sami live?
Three musicians, each with one instrument and one town.
Row
Instrument
Town
Rosa
blank
blank
Sami
blank
blank
Tomas
blank
blank
Clues
The instruments are the cello, the flute and the oboe; the towns are Ashford, Brindle and Calder. No instrument and no town is shared.
Tomas plays the flute.
The cellist lives in Brindle.
Tomas lives in Ashford.
Sami does not play the cello.
Show a hint
One clue names an instrument and a town but no person. Work out who plays that instrument first.
15. Three morning departures
Difficulty 3 of 5 · Tricky
Three trains leave a station at 09:10, 09:25 and 09:40, each from a different platform and each to a different town. From which platform does the 09:40 leave, and where is it going?
Three departures, each with one platform and one destination.
Row
Platform
Destination
09:10
blank
blank
09:25
blank
blank
09:40
blank
blank
Clues
The platforms are 1, 2 and 3; the destinations are Fenwick, Garrow and Hollin. No platform and no destination is shared.
The 09:25 leaves from platform 2.
The Fenwick train leaves from platform 3.
The 09:10 does not go to Garrow.
The Garrow train leaves from a lower-numbered platform than the Hollin train.
Show a hint
Work out which two platforms are still in play before you use the higher-and-lower comparison.
16. Three lockers at the pool
Difficulty 3 of 5 · Tricky
Iva, Jae and Kit each use one of lockers 1, 2 and 3, and each locker holds one item. Which locker does Jae use, and what is inside it?
Three people, each with one locker and one item inside it.
Row
Locker
Contents
Iva
blank
blank
Jae
blank
blank
Kit
blank
blank
Clues
The lockers are 1, 2 and 3; the items are boots, a helmet and a towel. No locker and no item is shared.
The towel is in locker 2.
Kit uses neither locker 1 nor locker 2.
Iva has the boots.
Show a hint
One clue rules the same person out of two lockers. Mark both crosses before you read anything else.
17. Three morning appointments
Difficulty 3 of 5 · Tricky
Lena, Mo and Nils have appointments at 10:00, 10:30 and 11:00, one each. Who is seen at 10:30, and who is seen at 11:00?
Three people, three appointment times, one appointment each.
Row
10:00
10:30
11:00
Lena
blank
blank
blank
Mo
blank
blank
blank
Nils
blank
blank
blank
Clues
The three appointments are at 10:00, 10:30 and 11:00, one person each.
Nils is seen immediately before Mo.
Lena is not seen at 11:00.
Show a hint
Treat the two consecutive appointments as one block and list every position that block could occupy.
18. Four flats, four floors
Difficulty 4 of 5 · Hard
A block has one flat on each of floors 1 to 4, and Priya, Quinn, Rafe and Suki live one to a flat. Who lives on the top floor?
Four floors, four residents, one resident to a floor.
Row
Priya
Quinn
Rafe
Suki
Floor 4 (top)
blank
blank
blank
blank
Floor 3
blank
blank
blank
blank
Floor 2
blank
blank
blank
blank
Floor 1
blank
blank
blank
blank
Clues
Each resident lives on a different floor.
Priya lives on floor 3.
Suki lives on neither floor 1 nor floor 4.
Rafe does not live on floor 4.
Show a hint
The person on the top floor is never named by any clue. Place everyone who is named and see who is left over.
19. Four scores, four roles
Difficulty 4 of 5 · Hard
Tara, Ubaid, Vera and Wren each took one role and each scored 61, 68, 74 or 80 on a shared exercise. Which role did Vera take, and what did she score?
Four candidates, each with one score and one role.
Row
Score
Role
Tara
blank
blank
Ubaid
blank
blank
Vera
blank
blank
Wren
blank
blank
Clues
The scores are 61, 68, 74 and 80 and the roles are analyst, designer, editor and planner. No score and no role is shared.
Vera scored higher than Tara but did not score the highest.
The editor scored 80.
Ubaid scored the lowest of the four.
Tara is the designer.
The planner scored the lowest of the four.
Show a hint
That comparison carries two restrictions at once. Write both of them down before you place any score.
20. Four books on a shelf
Difficulty 4 of 5 · Hard
Four books — Salt Road, Winter Ledger, Paper Kites and Quiet Fen — each have a different author and a different genre. Who wrote the romance, and which book is it?
Four books, each with one author and one genre.
Row
Author
Genre
Salt Road
blank
blank
Winter Ledger
blank
blank
Paper Kites
blank
blank
Quiet Fen
blank
blank
Clues
The authors are Ade, Bex, Cass and Dov; the genres are crime, history, romance and travel. No author and no genre is shared.
Salt Road is neither the crime novel nor the history book.
Bex wrote Quiet Fen.
The travel book was written by Cass.
Winter Ledger is the crime novel.
Quiet Fen is not the history book.
Dov wrote the history book.
Show a hint
Split the neither-nor clue into two separate crosses and see which title is left holding history.
21. Four stalls in a row
Difficulty 4 of 5 · Hard
Four market stalls stand in a row at positions 1 to 4, counting from the entrance. Which stall is at position 2?
Four stalls, four positions in a row, one stall to a position.
Row
Bread
Cheese
Flowers
Honey
Position 1
blank
blank
blank
blank
Position 2
blank
blank
blank
blank
Position 3
blank
blank
blank
blank
Position 4
blank
blank
blank
blank
Clues
The four stalls occupy positions 1 to 4, one stall to a position.
The bread stall is directly to the left of the cheese stall.
The honey stall is at position 4.
The flower stall is not next to the cheese stall.
Show a hint
Two stalls must stand side by side. List every place that pair could sit, then test each against the rest.
22. Four projects, four deadlines
Difficulty 4 of 5 · Hard
A team runs a survey, a rebuild, an audit and a launch. Each has a different lead and is due in a different month. Which project does Nia lead, and when is it due?
Four projects, each with one lead and one deadline month.
Row
Lead
Due month
Survey
blank
blank
Rebuild
blank
blank
Audit
blank
blank
Launch
blank
blank
Clues
The leads are Kai, Lin, Moss and Nia; the deadlines are March, April, May and June. No lead and no month is shared.
Kai leads the audit.
The rebuild is due neither in March nor in June.
The survey is due in March.
Lin's project is due in June.
Moss's project is due in May.
Show a hint
One clue closes two months for the same project. Shrink that project's row first, then test what remains.
23. Four labs, four topics
Difficulty 5 of 5 · Toughest
Anya, Boris, Cato and Dena each work in one of labs 1 to 4 and each study one topic. Which topic does Boris study, and in which lab?
Four researchers, each with one lab and one topic.
Row
Lab
Topic
Anya
blank
blank
Boris
blank
blank
Cato
blank
blank
Dena
blank
blank
Clues
The labs are 1, 2, 3 and 4; the topics are algae, basalt, coral and resin. No lab and no topic is shared.
Anya works in lab 1.
If Boris works in lab 2, then Dena studies basalt.
Dena studies coral.
Cato does not work in lab 2.
Boris works in a higher-numbered lab than Cato.
The algae study is carried out in lab 1.
Cato does not study resin.
Show a hint
One clue is an if-then. Check whether its second half is already false before you try to use its first half.
24. The clue you can spare
Difficulty 5 of 5 · Toughest
Four flights each leave from a different gate at a different time. The timetable below has exactly one solution, and exactly one of the last four clues can be deleted without making it ambiguous. Which clue is that?
Four flights, each with one gate and one departure time.
Row
Gate
Departure
Ardal flight
blank
blank
Brenn flight
blank
blank
Corve flight
blank
blank
Duns flight
blank
blank
Clues
The gates are 1, 2, 3 and 4; the departures are 06:00, 07:00, 08:00 and 09:00. No gate and no time is shared.
The Ardal flight leaves at 06:00.
The Corve flight leaves from gate 4.
The flight at gate 1 leaves at 07:00.
The Duns flight leaves later than the Corve flight.
The Ardal flight leaves from gate 3.
The Brenn flight does not leave from gate 2.
Show a hint
Delete one clue at a time and ask whether the timetable still has exactly one solution without it.
25. Four households, one assumption
Difficulty 5 of 5 · Toughest
Four households each live on a different street and keep a different vehicle. Which household keeps the bicycle, and on which street do they live?
Four households, each with one street and one vehicle.
Row
Street
Vehicle
Ahern
blank
blank
Brill
blank
blank
Cowan
blank
blank
Dray
blank
blank
Clues
The streets are Larch Row, Marsh Lane, Nettle Way and Oak Rise; the vehicles are a bicycle, an estate car, a motorbike and a van. No street and no vehicle is shared.
At least one of these two statements is true: the van is kept on Larch Row, or Dray lives on Marsh Lane.
Ahern lives on neither Larch Row nor Nettle Way.
Cowan lives on neither Nettle Way nor Oak Rise.
Neither Brill nor Cowan keeps the van.
Dray keeps neither the motorbike nor the van.
The estate car is kept on Nettle Way.
Show a hint
Nothing is placed outright. Take one half of the either-or clue as true and follow it until something breaks.
Skills these puzzles practise
Each category maps onto the shared aptitude constructs, so a puzzle that interests you has a lesson and a larger practice bank behind it: