Logic Grid Puzzles: Book-Due Date Grid and Firefighters Show Grid

Logic Grid Puzzle 1: Books and Due Dates

  • Overview: A four-person logic grid puzzle where each student is assigned a book title, a genre/category, and a due date. The goal is to determine which student has which book, which genre it belongs to, and on which date it is due.

  • Entities involved:

    • Students:
    • Jordan, Maggie, Kai, David
    • Books (titles): The Book Thief, The Diviners, Imaginary Borders, In Other Lands
    • Genres/Book types available (implied): Historical, Mystery, Nonfiction, Sci‑Fi/Fantasy
    • Due dates (calendar): 11/21, 11/30, 12/5, 12/1211/21, \, 11/30, \, 12/5, \, 12/12 (November 21; November 30; December 5; December 12)

  • Key clues from the transcript (point-by-point):

    • Point 1:
    • Jordan is not reading the Book Thief.
    • Jordan is not reading the Sci‑Fi/Fantasy book.
    • Therefore, the Sci‑Fi/Fantasy book is not the Book Thief, and the Sci‑Fi/Fantasy book is not Jordan's.
    • The November 21 due date is not the Book Thief and not the Sci‑Fi/Fantasy book.
    • Point 2:
    • Kai is not reading the Nonfiction book.
    • Point 3:
    • David's due date is before the due date of the Historical book, but after the due date of Imaginary Borders.
    • Consequences: David does not have the first or last due date; David does not read the Historical book; David does not read Imaginary Borders.
    • Point 4:
    • Maggie is reading the Mystery book.
    • Therefore, Maggie is the only one reading the Mystery book, and no one else reads it.
    • Additional deductions (from the narrative progression):
    • The Mystery book is identified as The Diviners (through the process of elimination given Maggie’s role and the constraint that the Book Thief is not due on 11/21).
    • Since Maggie reads The Diviners (Mystery), no one else reads The Diviners.
    • The Nonfiction book is Imaginary Borders (explicit statement).
    • Therefore, In Other Lands cannot be Nonfiction and cannot be Historical (per the deduction flow); In Other Lands must be Sci‑Fi/Fantasy.
    • The Book Thief is Historical (deduced later via the ordering constraints).
    • The November 21 due date is Maggie’s book (The Diviners, Mystery).
    • Therefore, the remaining assignments must fit the ordering constraint: Imaginary Borders is before David’s date, and the Historical book’s date is last.

  • Logical deductions and ordering (with reasoning):

    • Since Maggie has the Diviners (Mystery) and the Diviners is not due 11/21? Actually, 11/21 is Maggie’s due date and the Diviners is the Mystery; this fixes the 11/21 slot to Diviners.
    • Because Imaginary Borders is Nonfiction, and Kai cannot read Nonfiction, Kai cannot read Imaginary Borders.
    • Imaginary Borders is not Historical (nonfiction ≠ historical), so the Historical book must be a different title (The Book Thief).
    • David’s due date is after Imaginary Borders and before the Historical book:
      D( ext{Imaginary Borders}) < D( ext{David}) < D( ext{Historical})
    • With four dates to assign and the ordering constraint, the sequence must be: 11/21 (Maggie – Diviners, Mystery) → 11/30 → 12/5 → 12/12 (Historical – The Book Thief).
    • Because Imaginary Borders is Nonfiction and cannot be first or last by other constraints, it must be the 11/30 date.
    • In Other Lands cannot be Historical or Nonfiction, so it must be Sci‑Fi/Fantasy. Given David’s date is after Imaginary Borders (11/30) and before the Historical book (12/12), the remaining date slots force In Other Lands to 12/5, and identify David with In Other Lands (Sci‑Fi/Fantasy).
    • The Book Thief is Historical and ends up on 12/12; therefore Kai must be the one with The Book Thief on 12/12.
    • The remaining pairing then assigns:
    • Jordan must take Imaginary Borders (Nonfiction) on 11/30.
    • David takes In Other Lands (Sci‑Fi/Fantasy) on 12/5.
    • Maggie takes The Diviners (Mystery) on 11/21.
    • Kai takes The Book Thief (Historical) on 12/12.

  • Final solution for Puzzle 1 (summary mapping):

    • Maggie → The Diviners (Mystery) → due on 11/2111/21
    • Jordan → Imaginary Borders (Nonfiction) → due on 11/3011/30
    • David → In Other Lands (Sci‑Fi/Fantasy) → due on 12/512/5
    • Kai → The Book Thief (Historical) → due on 12/1212/12

  • Final notes on the reasoning process and how to approach similar puzzles:

    • Start with the explicit single-entity assignments (e.g., Maggie is Mystery) to lock a fact and prevent others from using the same item.
    • Use the process of elimination to reduce options for each person and each category.
    • Translate narrative clues into relative constraints (e.g., A before B, C not equal D).
    • Break ties by checking consistency across all clues; if one deduction forces an entire chain, verify other parts of the grid align with it.
    • Represent dates and comparative statements with simple inequalities when possible, e.g.:
      D( ext{Imaginary Borders}) < D( ext{David}) < D( ext{Historical})

  • Quick practice tips for solving logic grids:

    • Draw and label all four dimensions clearly: People, Books, Genres, Dates.
    • Mark definite assignments first (e.g., Maggie = Diviners).
    • Move left-to-right and top-to-bottom; use process of elimination to fill obvious blanks.
    • Keep track of what cannot be true for each item to prevent conflicts later.
    • When you reach a standstill, re-check relative constraints (e.g., ordering constraints) to unlock the remaining placements.

Logic Grid Puzzle 2: Firefighters and Show Details

  • Overview: A separate logic grid puzzle with four firefighters, four streets, four show start times, and four meals served after the show. Use process of elimination to map each person to a street, start time, and post-show meal.

  • Entities involved:

    • People: Mick North, Bill Cobb, Steve Tims, Nick North
    • Streets: Pinwheel Gardens, Swibb Street, Tinwheel Gardens, Rocket Road
    • Show start times: 07:00,07:15,07:30,07:4507:00, 07:15, 07:30, 07:45
    • Meals served after the show: Fish and Chips, Barbecue, Curry, (the fourth meal is not named in the transcript; use the remaining option in your deduction)

  • Key deductions from the transcript (step-by-step):

    • Mick North does not live on Pinwheel Gardens and does not have the last time slot.
    • Swibb Street’s residents had Barbecue, and no one else had Barbecue.
    • Bill Cobb lives on Rocket Road.
    • The 07:00 show had Fish and Chips.
    • The Squibb Street show had Barbecue; this connects to Nick North and Swibb Street (via process of elimination).

  • Deduction flow to final mapping (as described):

    • Nick North lives on Swibb Street, starts at 07:15, and had Barbecue (consistent with Swibb Street = Barbecue and the 07:15 time slot not conflicting with 07:00’s Fish and Chips).
    • Bill Cobb lives on Rocket Road and had Fish and Chips; his show time would be 07:00 (to satisfy the 07:00 Fish and Chips clue).
    • Steve Tims lives on Pinwheel Gardens and, by the timing clue that Nick’s show started earlier than the Pinwheel Gardens show, the Pinwheel Gardens show must be the later time; this is 07:30, with Curry.
    • Mick North cannot live on Pinwheel Gardens and cannot have the last time slot; with Nick on Swibb Street (07:15, Barbecue), Bill on Rocket Road (07:00, Fish and Chips), Steve on Pinwheel Gardens (07:30, Curry), the remaining street is Tinwheel Gardens for Mick North with the remaining time slot (07:45) and the remaining meal (the one not yet used).

  • Final solution for Puzzle 2 (summary mapping):

    • Bill Cobb → Rocket Road → Start time 07:0007:00 → Fish and Chips
    • Nick North → Swibb Street → Start time 07:1507:15 → Barbecue
    • Steve Tims → Pinwheel Gardens → Start time 07:3007:30 → Curry
    • Mick North → Tinwheel Gardens → Start time 07:4507:45 → Remaining meal (the meal not explicitly named in the clues)

  • Practical insights and caveats:

    • Be careful with similar-sounding street names or name spellings (e.g., Tinwheel vs Tinwheel/Tinwheel Gardens) to avoid misassignment; confirm via cross-checks like “last time slot” and “start earlier/later” relations.
    • Use the clue that a particular street had a unique meal to deduce who must be associated with that street (e.g., Swibb Street = Barbecue means the Barbecue entry must map to the person on Swibb Street).
    • When a clue fixes a variable (e.g., Bill Cobb is on Rocket Road), immediately lock that into the grid to reduce options for others.

Connections to class structure and exam prep

  • What the instructor emphasized:

    • These logic grids illustrate process elimination and structured deduction, not mere guessing.
    • Real on-class quizzes may be simpler than the most complex grid shown; expect grids of manageable size.
    • The quiz will cover material discussed since the last quiz; the instructor has not finalized the exact number of questions or marks yet.
    • Quizzes will be administered with a fixed window (open and close times) and a time limit once you click the quiz link.
    • You’ll have at least 24 hours to complete the quiz, but once you start, you have 1 hour to finish.
    • Tools to prepare: draw a 9x9 grid (as in Sudoku) for the quiz scratch work, and you may keep it during the quiz as scrap paper.
    • The next topics after the quiz include fundamental counting principles; be ready to shift to that area.

  • Ethical and practical implications discussed:

    • The instructor emphasizes integrity and proper use of the quiz window (no pausing, complete within the allotted hour once started).
    • The plan to post notes promptly helps students review and solidify understanding after class.

  • Quick study tips tailored to these puzzles:

    • Practice building and updating your own mini-grids from given clues.
    • Translate every clue into a constraint on the grid and apply it immediately.
    • Practice with multiple categories (people, items, dates, etc.) to get comfortable with cross-linking different dimensions.
    • Remember to check ordering constraints (A before B before C) as a guide to prune options quickly.

  • Additional logistical notes from the session:

    • The speaker plans to post notes right away after class.
    • Students may have questions at the start of class; the instructor will handle questions after the current activity and will provide more quiz details via an announcement.
    • A separate Sudoku exercise will be provided as part of the warm-up or practice in preparation for the quiz.

  • Summary: This session modeled two logic-grid puzzles (books with due dates, and firefighters with shows) and reinforced key problem-solving approaches: start with definite assignments, use process of elimination, translate clues into formal constraints, respect ordering relations, and verify consistency across all dimensions. The upcoming quiz will test these skills, with a fixed online window and a one-hour time limit after starting.

  • End-of-notes reminder: The notes will be posted promptly; use them to review and rehearse the puzzle-solving workflow before the next class.