How does the logic grid puzzle work?
A few people each have one of every trait: a pet, a drink, a colour they wear or a game they play. Each value belongs to exactly one person. The clues say who has what, who doesn't, and which traits go together. Fill in the answer table and press Check; it tells you how many answers are wrong, but not which.
Choose 3 people with 2 traits for a quick puzzle, or 4 people with 3 traits for a longer one. Every puzzle is new.
Can every Logic Grid Puzzle be solved without guessing?
Yes. Each puzzle is generated, then solved by a program that only makes the deductions a person would: crossing out, spotting the only place left for a value, and following a clue that links two traits. A puzzle is kept only if those deductions reach the whole answer, so it has exactly one answer, and any clue that isn't needed is removed. The site's tests check hundreds of puzzles this way.
How do you solve logic grid puzzles?
- Start with the firmest clues. "Ana has the cat" settles a cell at once; "either" clues narrow it to two.
- Use "exactly one each". When everyone but one person is ruled out for a value, it belongs to that person.
- Read linked clues both ways. "The cat's owner drinks tea" also means whoever doesn't drink tea can't have the cat.
- Cross out clues as you use them. Tap a clue to strike it through.
Is this the Einstein puzzle?
It's the same kind of puzzle. The best-known one, the Zebra Puzzle, was printed in Life International on 17 December 1962, with five houses and fifteen clues. It is often called Einstein's riddle, but there is no evidence that he wrote it. The puzzles here are smaller and new every game.
For another puzzle solved by deduction, try the Code Breaker; for chess, the Chess Puzzles.
How do you solve a logic grid puzzle step by step?
Here is a small one worked through. Ana, Ben and Cara each have one pet (a cat, a dog, a fish) and one drink (tea, coffee, juice). The clues: Ana doesn't have the dog. The cat's owner drinks tea. Ben drinks coffee. Ana drinks juice.
- Ben drinks coffee and Ana drinks juice, so Cara drinks the only drink left: tea.
- The cat's owner drinks tea, and Cara drinks tea, so Cara has the cat.
- Ana doesn't have the dog, and the cat is taken, so Ana has the fish.
- That leaves the dog for Ben.
Every step is one of three moves: the only option left, a clue that links two traits, or a "not" clue crossing something out. The puzzles here are generated so that those three moves are always enough.