Hazel MaplePUZZLES FOR A QUIET MOMENT

YOUR FIRST LOGIC GRID

How to solve
a logic grid puzzle

Start small. Use a cross for what cannot be true and a tick for what must be true. This worked example shows how three clues fit together, without guessing.

Follow the five steps

FROM THE LITTLE VILLAGE LOGIC CLUB

The early kettle

At the village cafe, Amira, Ben and Cleo each collect a different drink: Mint tea, Cocoa or Coffee. The slow kettle means one order is ready at a time. Who collects which drink, and who comes first, second and third?

Each person and each drink has a different place. You can sketch the two grids on paper, or follow the marks as they appear below.

The three clues

  1. The Mint tea entry is earlier in the order than Cleo.
  2. The Coffee entry is not first.
  3. Amira is immediately before the Mint tea entry.

“Earlier” means any earlier place. “Immediately before” means the place directly before.

Before you begin

Begin with an empty grid

Each neighbour collects one drink in a different place. The two grids share the same First, Second and Third columns, so a person and a drink in the same column belong together.

A tick means yes. A cross means no. A blank means we have not recorded an answer there yet. Each row and each column will eventually contain exactly one tick.

Neighbours and their places
NeighboursFirstSecondThird
AmiraNot recordedNot recordedNot recorded
BenNot recordedNot recordedNot recorded
CleoNot recordedNot recordedNot recorded
Drinks and their places
DrinksFirstSecondThird
Mint teaNot recordedNot recordedNot recorded
CocoaNot recordedNot recordedNot recorded
CoffeeNot recordedNot recordedNot recorded

✓ Yes× NoBlank: not recordedBorder: new this step

Read all five steps together
  1. Find the places that cannot work

    Clue 1 puts Mint tea before Cleo. Mint tea cannot be third: there would be no later place for Cleo. Cleo cannot be first: there would be no earlier place for Mint tea.

    Put a cross at Mint tea / Third and at Cleo / First. Leave the other squares blank for now.

  2. Record a direct “not” clue

    Clue 2 says Coffee is not first. We can record that immediately, even though we do not yet know where Coffee belongs.

    Put a cross at Coffee / First. A cross is useful information; it does not need to come with a tick.

  3. Join two clues to place Mint tea

    Clue 3 puts Amira immediately before Mint tea, so Mint tea cannot be first. We already ruled out third. Mint tea must be second, with Amira directly before it in first place.

    Tick Mint tea / Second and Amira / First. In each grid, cross out the other squares in the tick’s row and column: that name and that place are now taken.

  4. Finish placing the neighbours

    Cleo comes after Mint tea, which is second. That puts Cleo third. With Amira first and Cleo third, the only place left for Ben is second.

    Tick Cleo / Third and Ben / Second. Cross out Cleo / Second and Ben / Third. The neighbours’ grid is complete.

  5. Finish the drinks, then check every clue

    Coffee cannot be first, and Mint tea has taken second, so Coffee is third. Cocoa takes the remaining first place. Read the two grids by column: Amira has Cocoa, Ben has Mint tea, and Cleo has Coffee.

    Tick Coffee / Third and Cocoa / First, then cross out Cocoa / Third. Check: Mint tea is before Cleo; Coffee is not first; Amira is immediately before Mint tea. All three clues fit.

Three habits to take to your next puzzle

  1. Record what a clue rules out. “Not first” gives you a useful cross, even before you can place a tick.
  2. Keep “before” and “immediately before” separate. One tells you the order; the other also tells you that two entries are next to each other.
  3. Check the completed answer against every clue. If something does not fit, work back to the first mark you cannot explain.

This example uses two grids with places across the top. Other logic puzzles may use a larger combined grid; the same tick, cross and one-match rules apply to each pair of categories when every item has exactly one match.

TRY THE NEXT ONE YOURSELF

A parcel needs its owner.

The free sample includes this example and five more introductory puzzles, with printable grids, separate hints and worked answers. Try puzzle 2, “Parcels at the gate”, next.

Download six free puzzles

PDF · 29 pages · No email needed