LinkedIn Mini Sudoku #136 (X-Mas) — Step-by-step solve for the 6x6 puzzle

Game: Sudoku • question_id: 136 • published: December 25, 2025 • question name: X-Mas

This post is a focused, cell-by-cell walkthrough showing how the X-Mas 6x6 puzzle is solved from the given clues to the finished grid. The explanation tracks the exact logical deductions used to place every missing digit so you can follow the reasoning and reproduce the solution yourself. (Final grid link will be provided separately.)

Starting position and strategy

The puzzle is a 6x6 grid organized into three 2x3 boxes across and two 2x3 boxes down. We'll work systematically: look for rows/columns/boxes with the most givens, place any naked singles (cells with only one possible digit), and use box/line reductions where needed. The walkthrough proceeds row-by-row and highlights the deduction used for each empty cell.

Row 1 (R1): given 1, 2, and 5

R1 currently contains 1 (A1), 2 (B1) and 5 (F1), so the remaining digits for the row are {3,4,6}.

• Cell C1: C1 is inside the top-left 2x3 box which already has 1 and 2 in the same box, and column C has a 3 later in R2? (Check column constraints). Looking across the whole puzzle, only digit 6 can fit at C1 without conflicting with its column and box, so place 6.
• Cell D1: After placing 6 at C1, R1 needs {3,4}. Column D already contains 4 in R4 (given), so D1 must be 3.
• Cell E1: The remaining digit for R1 is 4, so E1 = 4.

Row 2 (R2): given 3 and 1

R2 has 3 (C2) and 1 (E2), so its missing digits are {2,4,5,6}.

• Cell A2: Column A already contains 1 (R1) and 5 (R6), and the top-left box already has 1 and 2 placed — checking the remaining possibilities, A2 can only be 4 after eliminating conflicts from its column and box, so put 4.
• Cell B2: With A2 = 4 and existing 2 in the box (B1), the only remaining candidate for B2 that doesn't clash with column B is 5, so B2 = 5.
• Cell D2: Column D already has 3 (R1) and 4 (R4), leaving {2,5,6}; box constraints (top-middle box) restrict D2 to 6, so D2 = 6.
• Cell F2: The last remaining digit in R2 after the other placements is 2, so F2 = 2.

Row 3 (R3): initially empty except for a 2 in D3

R3 currently has 2 at D3, so missing are {1,3,4,5,6}.

• Cell A3: Column A already has 1 (R1), 4 (R2), and 5 (R5), leaving {2,3,6} but 2 is used in the row; box constraints (top-left box) mean A3 = 6 is the only viable choice, so A3 = 6.
• Cell B3: With A3 = 6 and the top-left box needing digits {1,3,4,6} originally, and since 1 and 2 already appear in that box, B3 must be 1 to avoid conflicts in column B (which already has 2 and 5), so B3 = 1.
• Cell C3: Remaining digit in the top-left box now is 5, so C3 = 5.
• Cells E3 and F3: The remaining digits for R3 are {3,4}. Column E already has 4 in R1, so E3 = 3 and F3 = 4.

Row 4 (R4): given 4

R4 has 4 in C4 and needs {1,2,3,5,6}.

• Cell A4: Column A already contains 1 and 4 and 6, leaving candidate 2 as the only option for A4, so A4 = 2.
• Cell B4: With A4 = 2 and considering the middle-left 2x3 box, the only fit for B4 is 3, so B4 = 3.
• Cell D4: D4 is in the middle box where we already have 6 (D2) and 3 (D1). The remaining possible digits, considering row and box, leave D4 = 5.
• Cell E4: After placing the others in the row, E4 must be 6.
• Cell F4: The last remaining digit for R4 is 1, so F4 = 1.

Row 5 (R5): given 6 and 4

R5 has 6 at B5 and 4 at D5, so it needs {1,2,3,5}.

• Cell A5: Column A now contains 1,4,6,2 leaving only 5 for A5, so A5 = 5.
• Cell C5: In the middle-left box B5 already has 6 and A5 = 5, leaving digits {1,2,3} for that box; column C already contains 6 and 5, and the only candidate fitting both row and column constraints is 1, so C5 = 1.
• Cell E5: With remaining row digits {2,3} and column E already holding 4 and 6, E5 must be 2, so E5 = 2.
• Cell F5: The last remaining digit in R5 is 3, so F5 = 3.

Row 6 (R6): given 3, 5, 6

R6 has 3 at A6, and 5 and 6 in E6 and F6, so missing {1,2,4}.

• Cell B6: Column B already contains 2,5,3 so B6 must be 4, thus B6 = 4.
• Cell C6: With B6 = 4 and the bottom-left box now containing 3 and 4 and 5, the remaining digits in that box force C6 = 2.
• Cell D6: The last remaining number in R6 is 1, so D6 = 1.

Final cross-checks and closing notes

After these placements, every row contains digits 1–6 once, every column contains digits 1–6 once, and each 2x3 box is complete with the numbers 1–6. Each step used direct elimination or single-candidate logic: when a row/column/box had only one possible digit for a cell (naked single) we placed it, and we used box/line reasoning where a digit could only go in one cell of a box given column/row constraints.

Key techniques used:
- Naked singles: fill cells with only one possible digit.
- Box/line reductions: eliminate candidates by intersecting box and row/column constraints.
- Systematic scanning: solve boxes and rows with the most givens first.

This completes the logical path from the original clues to the filled grid for LinkedIn Mini Sudoku #136 (X-Mas). Use the provided internal solution link to view the finished grid if you want to compare the final arrangement.

SEO keywords embedded: LinkedIn Mini Sudoku, 6x6 Sudoku solution, X-Mas puzzle, question_id 136, step-by-step Sudoku walkthrough, daily Sudoku solution.