Learn · Thinking Skills · 5 min

Logic puzzles: use a grid

“Ava, Ben and Cara each own one pet…” — these are only hard if you try to keep them in your head. Draw a grid and the clues do the work:

✗a clue that rules something out — cross that cell
✓the last empty space in a column must be a tick
rowone tick means the rest of that row is crosses

See it: three clues, one grid, no guessing

Ava, Ben and Cara each own one pet — a cat, a dog or a fish. Apply the clues one at a time.

	cat	dog	fish
Ava	·	·	·
Ben	·	·	·
Cara	·	·	·

Press Clue 1 to start. Nothing is known yet.

Now — the move everyone misses

A tick does double work

Most students cross out what the clues say and then stop, stuck. Every tick you place gives you four more crosses for free — the rest of its row and the rest of its column. That cascade is what finishes the puzzle.

① A clue says no → cross one cell
② A row or column with one space left → that space is a tick
③ Every new tick → cross the rest of its row and its column
④ Repeat ② and ③ until the grid is full — you never guess

Tips & tricks

“Either / or” clues are two crosses

“The cat is Ava’s or Ben’s” tells you nothing about Ava or Ben — it tells you Cara has no cat.

Ordering puzzles — draw positions, not a grid

“Sam finished before Kim” → a line of places. Put in the fixed ones first, then slot the rest.

“Directly before” is stronger than “before”

“Directly” means touching — no room for anyone between. Read those two words carefully.

Start with the clue that mentions the fewest options

A clue naming one person and one thing settles a cell immediately. Save the vague ones for later.

If you must guess, you missed a deduction

Exam logic puzzles always have exactly one answer reachable by pure elimination. Re-read the clue list before guessing.

Now you try — 0/3

Dev, Eli and Fay each play one sport — soccer, tennis or chess.

Eli does not play tennis.
Dev plays neither soccer nor chess.
Fay does not play chess.

1. What does Dev play?

2. Who plays chess?

3. Once you know Dev plays tennis, what can you cross out straight away?

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