Puzzle & Pay Lab

A repeatable grid method

How to solve a logic puzzle

A logic puzzle gives you categories and clues. Your job is to place one value from each category into each row so that every clue is true. The steps below work for any Puzzle & Pay puzzle.

  1. 1

    Draw the grid. Put one category down the side and one across the top. Repeat for each pair of categories.

  2. 2

    Read all clues once. Mark the clues that name a value directly.

  3. 3

    Use X for 'cannot be true' and a dot for 'must be true'.

  4. 4

    When a dot appears, put X in every other row and column in that category.

  5. 5

    Work from the most specific clue to the least specific clue.

  6. 6

    Stop when every row has one value from each category. Check every clue against the completed grid.

Worked example

Mini-grid: three learners, three books, three seats

Labels

  • Learners: Ivy, Kai, Lio
  • Books: atlas, diary, manual
  • Seats: seat 1, seat 2, seat 3

Clues

  1. Ivy did not read the atlas.
  2. Kai sat in seat 2.
  3. The diary was read in seat 1.
  4. Lio did not sit in seat 3.

Deductions

  1. Kai is in seat 2. So Ivy and Lio are in seats 1 and 3.
  2. Lio is not in seat 3. So Lio is in seat 1 and Ivy is in seat 3.
  3. The diary is in seat 1. Seat 1 is Lio. So Lio read the diary.
  4. Ivy is in seat 3. Ivy did not read the atlas. The atlas cannot be Lio's because Lio has the diary. So Kai read the atlas.
  5. The remaining book is the manual, and the remaining reader is Ivy. Ivy read the manual.

Solution

  • Ivy — manual — seat 3
  • Kai — atlas — seat 2
  • Lio — diary — seat 1

Five mistakes to avoid