LinkedIn Mini Sudoku #137 (Boxing Day) - December 26, 2025: Step-by-Step 6x6 Solution Walkthrough

Crack today's LinkedIn Mini Sudoku #137 Boxing Day challenge, Question ID 137, with this logical breakdown. This 6x6 puzzle requires filling rows, columns, and 2x3 boxes with digits 1-6 uniquely. Starting from the given clues, we'll use naked singles, exclusions, and box completions to solve every cell progressively.

Visualizing the Starting Grid

  1 2 3 4 5 6
1 . . . . . .
2 1 . . . . 4
3 . 2 . . 5 .
4 3 . . . . 6
5 . . 1 2 . .
6 . . 4 3 . .

Clues: Row2 Col1=1, Row2 Col6=4; Row3 Col2=2, Row3 Col5=5; Row4 Col1=3, Row4 Col6=6; Row5 Col3=1, Row5 Col4=2; Row6 Col3=4, Row6 Col4=3.

Step 1: Fill Naked Singles in Rows and Boxes

Examine Row 2: Contains 1 (Col1) and 4 (Col6). Missing 2,3,5,6. Look at columns and top-right 2x3 box (Rows1-2, Cols4-6).

• Row 2 Col5 can't be 5 (blocked by Row3 Col5=5 in same column). Can't be 4 (already in row). Box needs 2,3,5,6 but exclusions narrow it.
• Actually, focus on box completions first. Bottom-left box (Rows5-6, Cols1-2) has no clues yet, but let's scan for singles.

Row 4 has 3 (Col1), 6 (Col6). Missing 1,2,4,5. Col2 in Row4: Can't be 2 (Row3 Col2=2), can't be 1 (Row5 Col3=1 intersects), but check box.

Step 2: Top-Left Box Analysis (Rows1-2, Cols1-3)

Clues: Row2 Col1=1. Row3 Col2=2 affects indirectly.

• Missing 2,3,4,5,6. Row1 Col2 can't be 1 (row2), can't be 2 (row3 col2 same col), can't be 3 (row4 col1 same box? Wait, different box).
• Row1 all empty. But column exclusions: Col1 has Row2=1, Row4=3 so Row1 Col1 possibilities 2,4,5,6.
• Naked single emerges in Row5: After clues, Row5 needs 3,4,5,6 (1,2 present). Col1 Row5 can't be 1,2,3 (row4=3),4 (row6 col3=4 col), but logic chains.

Step 3: Column Completions and Pointing Pairs

Column 6: Clues Row2=4, Row4=6. Missing 1,2,3,5. Row1 Col6 only spot for certain numbers.

• Row3 Col6 can't be 4,6 (column), can't be 5 (row3=5 col5), can't be 2 (row3 col2). Leaves 1 or 3.
• Bottom-right box (Rows5-6 Cols4-6): Clues Row5 Col4=2, Row6 Col3=4? Col3 is left box. Row6 Col4=3. So box has 2,3. Missing 1,5,6.
• Row5 Col6 can't be 2 (row), 3 (row6 col4 same col? Col4), col6 has 4,6 so can't 4,6. Leaves 1,5.

Key insight: Focus on number 5 placement. 5 is in Row3 Col5. Column 5 can't have another 5, so scan.

Step 4: Box-Line Reduction for Middles

Middle-left box (Rows3-4 Cols1-3): Clues Row3 Col2=2, Row4 Col1=3. Missing 1,4,5,6.

• Row3 Col1 can't be 2 (row), 3 (row4 col1 same col), 5 (row col5). Leaves 1,4,6 but 1 in row5 col3 same box? Row5 different box.
• Row3 Col1: Column1 has 1 (r2),3 (r4) so can't 1,3. Leaves 4,6 but row3 has 2,5 so ok. But naked single: Actually, 6 blocked by row4 col6 same row? No col6.

Place first definite: Row1 Col1. Column1: r2=1,r4=3. Row1 box top-left needs unique. But chain: Let's place obvious.

Progressing Fills: First Breakthroughs

Start filling confirmed cells:

1. Row4 Col5: Look at row4 missing 1,2,4,5. Col5 has r3=5 so not 5. Col2 possibilities narrow.
2. Critical: Bottom box row6: Col3=4, Col4=3. Row6 missing 1,2,5,6 in cols1,2,5,6.
3. Col1 row6 can't be 1 (r2),3 (r4),4 (r6 col3). Leaves 2,5,6.
4. But box bottom-left (r5-6 c1-3): r5 c3=1, r6 c3=4. So box has 1,4. Missing 2,3,5,6 but r6 c4=3 is right box.

Using exclusion: Row5 Col1 is 6. Why? Row5 has 1(c3),2(c4). Missing 3,4,5,6. Col1 has 1(r2),3(r4). So can't 1,3. Row6 col3=4 so 4 in box, but for col1. Actually, standard logic shows Row5 Col1 only 6 possible after listing possibilities for all.

Mid-Game: Chaining Exclusions

Once Row5 Col1=6 placed, Row5 Col5=4 (only left after exclusions: can't 1,2,6 placed, 3? but col3 row6=4 no, wait specific).

• Row5 Col6=5 (now only spot).
• Column6 now has r2=4,r4=6,r5=5 so r1 col6=2, r3 col6=3, r6 col6=1.

This cascades: Row1 Col6=2 fills top-right box almost.

Late Game: Final Box Completions

Top row now: With r1 c6=2, missing others. Row1 Col5=1 (only possible).

1. Row2 Col2=6 (row2 missing, col2 has r3=2).
2. Continue: Row2 Col3=2? No, logic fills Row2 Col5=3, etc.

Row3 Col1=4, Row3 Col3=6, Row3 Col4=1, Row3 Col6=3 as above.

Row1 fills: Col1=5 (only), Col2=4, Col3=3, Col4=6.

Row6 Col1=2, Col2=5, Col5=6.

Row4 Col2=1, Col3=5, Col4=4.

Row2 Col4=5, etc. Each step uses row/column/box uniqueness to pinpoint the lone possibility.

Final Tips for LinkedIn Mini Sudoku 6x6

Daily puzzles like #137 Boxing Day reward patience with singles and eliminations. Practice on LinkedIn games for speed. Check your grid against rules—no repeats!

Mastered this? Tackle tomorrow's Question ID for more LinkedIn Mini Sudoku wins.