| Easy Puzzle #6 - One Possible Solution Approach | ||||||||||||
| NB: There is only one final solution to this Sudoku puzzle | ||||||||||||
| A | B | C | D | E | F | G | H | I | ||||
| 1 | ||||||||||||
| 2 | AA | BB | CC | Reference to 3x3 Blocks AA, BB & CC | ||||||||
| 3 | ||||||||||||
| 4 | ||||||||||||
| 5 | DD | EE | FF | Reference to 3x3 Blocks DD, EE & FF | ||||||||
| 6 | ||||||||||||
| 7 | ||||||||||||
| 8 | GG | HH | II | Reference to 3x3 Blocks GG, HH & II | ||||||||
| 9 | ||||||||||||
| A | B | C | D | E | F | G | H | I | ||||
| 1 | 1 | 2 | Easy Puzzle #6 - October 6, 2005 | |||||||||
| 2 | 7 | 3 | 6 | 5 | 1 | Original puzzle as published on joe-ks.com | ||||||
| 3 | 3 | 2 | 1 | 4 | 7 | |||||||
| 4 | 8 | 7 | 9 | 5 | ||||||||
| 5 | 7 | 6 | 5 | 8 | 4 | |||||||
| 6 | 9 | 2 | 4 | 6 | 3 | |||||||
| 7 | 7 | 9 | 5 | 3 | 6 | |||||||
| 8 | 6 | 1 | 9 | |||||||||
| 9 | 3 | 9 | 2 | 5 | 1 | |||||||
| A | B | C | D | E | F | G | H | I | ||||
| 1 | 1 | 3 | 2 | Step 1: #3 is in Rows 2 & 3: #3 MUST go in Cell G1 | ||||||||
| 2 | 7 | 3 | 6 | 5 | 1 | (NB: cant go in H1 as #3 is in Column H @ H7) | ||||||
| 3 | 3 | 2 | 1 | 4 | 7 | |||||||
| 4 | 8 | 7 | 9 | 5 | ||||||||
| 5 | 7 | 6 | 5 | 8 | 4 | |||||||
| 6 | 9 | 2 | 4 | 6 | 3 | |||||||
| 7 | 7 | 9 | 5 | 3 | 6 | Step 2: #5 is in Rows 7 & 9: #5 MUST go in Cell C8 | ||||||
| 8 | 6 | 1 | 5 | 9 | ||||||||
| 9 | 3 | 9 | 2 | 5 | 1 | |||||||
| A | B | C | D | E | F | G | H | I | ||||
| 1 | 1 | 3 | 2 | Step 3: #3 is in Columns A & B: #3 MUST go in Cell C5 | ||||||||
| 2 | 7 | 3 | 6 | 5 | 1 | 9 | ||||||
| 3 | 3 | 2 | 1 | 4 | 7 | Step 4: #6 is in Columns E & F: #6 MUST go in Cell D9 | ||||||
| 4 | 8 | 7 | 9 | 5 | (NB: cant go in D8 as #6 is in Row 8 @ A8) | |||||||
| 5 | 7 | 6 | 3 | 5 | 8 | 4 | ||||||
| 6 | 9 | 2 | 4 | 6 | 3 | Step 5: #9 is in Columns G & H: #9 MUST go in Cell I2 | ||||||
| 7 | 7 | 9 | 5 | 3 | 6 | |||||||
| 8 | 6 | 1 | 5 | 9 | ||||||||
| 9 | 3 | 6 | 9 | 2 | 5 | 1 | ||||||
| A | B | C | D | E | F | G | H | I | ||||
| 1 | 1 | 3 | 2 | Step 6: Only one # required for Column I | ||||||||
| 2 | 7 | 3 | 6 | 5 | 1 | 9 | #8 MUST go in Cell I8 | |||||
| 3 | 3 | 2 | 1 | 4 | 7 | |||||||
| 4 | 8 | 7 | 9 | 5 | Step 7: #8 is in Rows 4 & 5: #8 MUST go in Cell F6 | |||||||
| 5 | 7 | 6 | 3 | 5 | 8 | 4 | ||||||
| 6 | 9 | 2 | 4 | 6 | 8 | 3 | ||||||
| 7 | 7 | 9 | 5 | 3 | 6 | |||||||
| 8 | 6 | 1 | 5 | 9 | 8 | |||||||
| 9 | 3 | 6 | 9 | 2 | 5 | 1 | ||||||
| A | B | C | D | E | F | G | H | I | ||||
| 1 | 1 | 3 | 6 | 2 | Step 8: #6 is in Rows 5 & 6: #6 MUST go in Cell G4 | |||||||
| 2 | 7 | 3 | 6 | 5 | 1 | 9 | ||||||
| 3 | 3 | 2 | 1 | 4 | 7 | Step 9: Now #6 is in Columns G & I: #6 MUST go in Cell H1 | ||||||
| 4 | 8 | 7 | 6 | 9 | 5 | |||||||
| 5 | 7 | 6 | 3 | 5 | 8 | 4 | Step 10: #1 is in Rows 8 & 9: #1 MUST go in Cell F7 | |||||
| 6 | 9 | 2 | 4 | 6 | 8 | 3 | (because #1 is already in Column E @ E3) | |||||
| 7 | 7 | 9 | 5 | 1 | 3 | 6 | ||||||
| 8 | 6 | 1 | 5 | 9 | 8 | |||||||
| 9 | 3 | 6 | 9 | 2 | 5 | 1 | ||||||
| A | B | C | D | E | F | G | H | I | ||||
| 1 | 1 | 3 | 6 | 2 | Step 11: Only one # required for Block CC | |||||||
| 2 | 7 | 3 | 6 | 5 | 1 | 9 | #8 MUST go in Cell G3 | |||||
| 3 | 3 | 2 | 6 | 1 | 8 | 4 | 7 | |||||
| 4 | 8 | 3 | 7 | 6 | 9 | 5 | Step #12: #6 is in Rows 1 & 2: #6 MUST go in Cell C3 | |||||
| 5 | 7 | 6 | 3 | 5 | 8 | 4 | ||||||
| 6 | 9 | 2 | 4 | 6 | 8 | 3 | Step 13: #3 is in Rows 5 & 6: #3 MUST go in Cell E4 | |||||
| 7 | 7 | 9 | 5 | 1 | 3 | 6 | ||||||
| 8 | 6 | 1 | 5 | 3 | 9 | 8 | Step 14: #3 is in Rows 7 & 9: #3 MUST go in Cell F8 | |||||
| 9 | 3 | 6 | 9 | 2 | 5 | 1 | (see Step 13 re #3s now in Columns D & E ) | |||||
| A | B | C | D | E | F | G | H | I | ||||
| 1 | 1 | 3 | 6 | 2 | Step 15: Row 3 needs two more #s: #5 & #9: | |||||||
| 2 | 7 | 3 | 6 | 5 | 1 | 9 | #5 can't go in Cell D3 ('cause #5 is in Column D @ D7), so | |||||
| 3 | 3 | 2 | 6 | 9 | 1 | 5 | 8 | 4 | 7 | #5 MUST go in Cell F3, and #9 MUST go in Cell D3 | ||
| 4 | 8 | 3 | 7 | 6 | 9 | 5 | ||||||
| 5 | 7 | 6 | 3 | 5 | 9 | 8 | 4 | Step 16: #9 is now in Columns D & E: #9 MUST go in Cell F5 | ||||
| 6 | 9 | 2 | 4 | 6 | 8 | 3 | ||||||
| 7 | 7 | 9 | 5 | 1 | 3 | 6 | ||||||
| 8 | 6 | 1 | 5 | 3 | 9 | 8 | ||||||
| 9 | 3 | 6 | 9 | 2 | 5 | 1 | ||||||
| A | B | C | D | E | F | G | H | I | ||||
| 1 | 1 | 3 | 6 | 2 | Step 17: #2 is needed in Block F: #2 MUST go in Cell G5 | |||||||
| 2 | 7 | 3 | 2 | 6 | 5 | 1 | 9 | (because #2 in Row 6 excludes Cells G6 & H6 ) | ||||
| 3 | 3 | 2 | 6 | 9 | 1 | 5 | 8 | 4 | 7 | |||
| 4 | 8 | 3 | 7 | 6 | 9 | 5 | Step 18: #2 is in Rows 1 & 3: #2 MUST go in Cell E2 | |||||
| 5 | 7 | 6 | 3 | 5 | 9 | 2 | 8 | 4 | ||||
| 6 | 9 | 2 | 4 | 6 | 8 | 3 | ||||||
| 7 | 7 | 9 | 5 | 1 | 3 | 6 | ||||||
| 8 | 6 | 1 | 5 | 3 | 9 | 8 | ||||||
| 9 | 3 | 6 | 9 | 2 | 5 | 1 | ||||||
| A | B | C | D | E | F | G | H | I | ||||
| 1 | 9 | 1 | 3 | 6 | 2 | Step 19: Block II needs a #2: #2 MUST go in Cell H8 | ||||||
| 2 | 7 | 3 | 2 | 6 | 5 | 1 | 9 | (because #2s in Row 9 & Column G exclude G7 & G9) | ||||
| 3 | 3 | 2 | 6 | 9 | 1 | 5 | 8 | 4 | 7 | |||
| 4 | 8 | 3 | 7 | 6 | 9 | 5 | Step 20: Now we have #2 in Rows 8 & 9: #2 MUST go in A7 | |||||
| 5 | 7 | 6 | 3 | 5 | 9 | 2 | 8 | 4 | ||||
| 6 | 9 | 2 | 4 | 6 | 8 | 3 | Step 21: #9 is in Rows 2 & 3: #9 MUST go in Cell A1 | |||||
| 7 | 2 | 7 | 9 | 5 | 1 | 3 | 6 | (because #9 in Column B @ B6 excludes B1 ) | ||||
| 8 | 6 | 1 | 5 | 3 | 9 | 2 | 8 | |||||
| 9 | 3 | 6 | 9 | 2 | 5 | 1 | ||||||
| A | B | C | D | E | F | G | H | I | ||||
| 1 | 9 | 1 | 3 | 6 | 2 | Step 22: Block HH needs #8: #8 MUST go in Cell E7 | ||||||
| 2 | 7 | 3 | 2 | 6 | 5 | 1 | 9 | (because #8 in Row 8 @ I8 excludes Cells D8 & E8 ) | ||||
| 3 | 3 | 2 | 6 | 9 | 1 | 5 | 8 | 4 | 7 | |||
| 4 | 8 | 3 | 7 | 6 | 9 | 5 | Step 23: Now there are #8's in Rows 7 & 8 | |||||
| 5 | 7 | 6 | 3 | 5 | 9 | 2 | 8 | 4 | #8 MUST go in Cell A9 (because of #8 in Column C @ C4) | |||
| 6 | 9 | 2 | 4 | 6 | 8 | 1 | 3 | |||||
| 7 | 2 | 7 | 9 | 5 | 8 | 1 | 3 | 6 | Step 24: #1 is in Columns H & I: #1 MUST go in Cell G6 | |||
| 8 | 6 | 1 | 5 | 3 | 9 | 2 | 8 | |||||
| 9 | 8 | 3 | 6 | 9 | 2 | 5 | 1 | |||||
| A | B | C | D | E | F | G | H | I | ||||
| 1 | 9 | 5 | 1 | 3 | 6 | 2 | Step 25: Only 1 number left for both Column H & Block FF: | |||||
| 2 | 7 | 3 | 2 | 6 | 5 | 1 | 9 | #7 MUST go in Cell H6 | ||||
| 3 | 3 | 2 | 6 | 9 | 1 | 5 | 8 | 4 | 7 | |||
| 4 | 8 | 3 | 7 | 6 | 9 | 5 | Step 26: Only 1 number left for Row 6: #5 MUST go in Cell A6 | |||||
| 5 | 7 | 6 | 3 | 5 | 9 | 2 | 8 | 4 | ||||
| 6 | 5 | 9 | 2 | 4 | 6 | 8 | 1 | 7 | 3 | Step 27: Now we have #5 in Columns A & C: | ||
| 7 | 2 | 7 | 9 | 5 | 8 | 1 | 3 | 6 | #5 MUST go in Cell B1 | |||
| 8 | 6 | 1 | 5 | 3 | 9 | 2 | 8 | (because #5 in Row 2 @ G2 excludes Cell B2) | ||||
| 9 | 8 | 3 | 6 | 9 | 2 | 5 | 1 | |||||
| A | B | C | D | E | F | G | H | I | ||||
| 1 | 9 | 5 | 1 | 3 | 6 | 2 | Step 28: Only 1 # required for both Column C & Block GG: | |||||
| 2 | 7 | 3 | 2 | 6 | 5 | 1 | 9 | #4 MUST go in Cell C9 | ||||
| 3 | 3 | 2 | 6 | 9 | 1 | 5 | 8 | 4 | 7 | |||
| 4 | 8 | 3 | 7 | 6 | 9 | 5 | Step 29: Only 1 required for Row 5: #1 MUST go in Cell D5 | |||||
| 5 | 7 | 6 | 3 | 1 | 5 | 9 | 2 | 8 | 4 | |||
| 6 | 5 | 9 | 2 | 4 | 6 | 8 | 1 | 7 | 3 | |||
| 7 | 2 | 7 | 9 | 5 | 8 | 1 | 3 | 6 | ||||
| 8 | 6 | 1 | 5 | 3 | 9 | 2 | 8 | |||||
| 9 | 8 | 3 | 4 | 6 | 9 | 2 | 5 | 1 | ||||
| A | B | C | D | E | F | G | H | I | ||||
| 1 | 9 | 5 | 1 | 4 | 3 | 6 | 2 | Step 30: Only 1 # required for Row 7: #4 MUST go in Cell G7 | ||||
| 2 | 7 | 3 | 2 | 6 | 5 | 1 | 9 | |||||
| 3 | 3 | 2 | 6 | 9 | 1 | 5 | 8 | 4 | 7 | Step 31: Only 1 # req'd for Column G: #7 MUST go in Cell G9 | ||
| 4 | 8 | 3 | 7 | 6 | 9 | 5 | ||||||
| 5 | 7 | 6 | 3 | 1 | 5 | 9 | 2 | 8 | 4 | Step 32: Only 1 # req'd for Column F: #4 MUST go in Cell F1 | ||
| 6 | 5 | 9 | 2 | 4 | 6 | 8 | 1 | 7 | 3 | |||
| 7 | 2 | 7 | 9 | 5 | 8 | 1 | 4 | 3 | 6 | Step 33: #4 is now in Columns D & F: | ||
| 8 | 6 | 1 | 5 | 4 | 3 | 9 | 2 | 8 | #4 now MUST go in Cell E8 | |||
| 9 | 8 | 3 | 4 | 6 | 9 | 2 | 7 | 5 | 1 | |||
| A | B | C | D | E | F | G | H | I | ||||
| 1 | 9 | 5 | 1 | 7 | 4 | 3 | 6 | 2 | Step 34: Only 1 # req'd for Block HH: #7 MUST go in Cell D8 | |||
| 2 | 7 | 3 | 2 | 6 | 5 | 1 | 9 | |||||
| 3 | 3 | 2 | 6 | 9 | 1 | 5 | 8 | 4 | 7 | Step 35: Now we have #7 in Columns D & F | ||
| 4 | 8 | 3 | 7 | 6 | 9 | 5 | #7 MUST go in Cell E1 | |||||
| 5 | 7 | 6 | 3 | 1 | 5 | 9 | 2 | 8 | 4 | |||
| 6 | 5 | 9 | 2 | 4 | 6 | 8 | 1 | 7 | 3 | |||
| 7 | 2 | 7 | 9 | 5 | 8 | 1 | 4 | 3 | 6 | |||
| 8 | 6 | 1 | 5 | 7 | 4 | 3 | 9 | 2 | 8 | |||
| 9 | 8 | 3 | 4 | 6 | 9 | 2 | 7 | 5 | 1 | |||
| A | B | C | D | E | F | G | H | I | ||||
| 1 | 9 | 5 | 1 | 8 | 7 | 4 | 3 | 6 | 2 | Step 36: Only 1 # req'd for Row 1 & Block BB: | ||
| 2 | 7 | 3 | 2 | 6 | 5 | 1 | 9 | #8 MUST go in Cell D1 | ||||
| 3 | 3 | 2 | 6 | 9 | 1 | 5 | 8 | 4 | 7 | |||
| 4 | 8 | 2 | 3 | 7 | 6 | 9 | 5 | Step 37: Only 1 # req'd for Column D: | ||||
| 5 | 7 | 6 | 3 | 1 | 5 | 9 | 2 | 8 | 4 | #2 MUST go in Cell D4 | ||
| 6 | 5 | 9 | 2 | 4 | 6 | 8 | 1 | 7 | 3 | |||
| 7 | 2 | 7 | 9 | 5 | 8 | 1 | 4 | 3 | 6 | |||
| 8 | 6 | 1 | 5 | 7 | 4 | 3 | 9 | 2 | 8 | |||
| 9 | 8 | 3 | 4 | 6 | 9 | 2 | 7 | 5 | 1 | |||
| A | B | C | D | E | F | G | H | I | ||||
| 1 | 9 | 5 | 1 | 8 | 7 | 4 | 3 | 6 | 2 | Step 38: Block AA requires 2 #s: #4 & #8: | ||
| 2 | 4 | 7 | 3 | 2 | 6 | 5 | 1 | 9 | #4 MUST go in Cell A2 (because #8 in Column A @ A9 | |||
| 3 | 3 | 2 | 6 | 9 | 1 | 5 | 8 | 4 | 7 | excludes #8 going in Cell A2) | ||
| 4 | 4 | 8 | 2 | 3 | 7 | 6 | 9 | 5 | ||||
| 5 | 7 | 6 | 3 | 1 | 5 | 9 | 2 | 8 | 4 | Step 39: Now we have #4 in Columns A & C: | ||
| 6 | 5 | 9 | 2 | 4 | 6 | 8 | 1 | 7 | 3 | #4 MUST go in Cell B4 | ||
| 7 | 2 | 7 | 9 | 5 | 8 | 1 | 4 | 3 | 6 | |||
| 8 | 6 | 1 | 5 | 7 | 4 | 3 | 9 | 2 | 8 | |||
| 9 | 8 | 3 | 4 | 6 | 9 | 2 | 7 | 5 | 1 | |||
| A | B | C | D | E | F | G | H | I | ||||
| 1 | 9 | 5 | 1 | 8 | 7 | 4 | 3 | 6 | 2 | Step 40: Only 1 # req'd for Row 2: #8 MUST go in Cell B2 | ||
| 2 | 4 | 8 | 7 | 3 | 2 | 6 | 5 | 1 | 9 | |||
| 3 | 3 | 2 | 6 | 9 | 1 | 5 | 8 | 4 | 7 | Step 41: Only 1 # req'd for Row 4: #1 MUST go in Cell A4 | ||
| 4 | 1 | 4 | 8 | 2 | 3 | 7 | 6 | 9 | 5 | |||
| 5 | 7 | 6 | 3 | 1 | 5 | 9 | 2 | 8 | 4 | |||
| 6 | 5 | 9 | 2 | 4 | 6 | 8 | 1 | 7 | 3 | |||
| 7 | 2 | 7 | 9 | 5 | 8 | 1 | 4 | 3 | 6 | |||
| 8 | 6 | 1 | 5 | 7 | 4 | 3 | 9 | 2 | 8 | |||
| 9 | 8 | 3 | 4 | 6 | 9 | 2 | 7 | 5 | 1 | |||
| A | B | C | D | E | F | G | H | I | ||||
| 1 | 9 | 5 | 1 | 8 | 7 | 4 | 3 | 6 | 2 | 45 | Final Proof: | |
| 2 | 4 | 8 | 7 | 3 | 2 | 6 | 5 | 1 | 9 | 45 | - All Rows add up to 45; | |
| 3 | 3 | 2 | 6 | 9 | 1 | 5 | 8 | 4 | 7 | 45 | ||
| 4 | 1 | 4 | 8 | 2 | 3 | 7 | 6 | 9 | 5 | 45 | ||
| 5 | 7 | 6 | 3 | 1 | 5 | 9 | 2 | 8 | 4 | 45 | ||
| 6 | 5 | 9 | 2 | 4 | 6 | 8 | 1 | 7 | 3 | 45 | ||
| 7 | 2 | 7 | 9 | 5 | 8 | 1 | 4 | 3 | 6 | 45 | ||
| 8 | 6 | 1 | 5 | 7 | 4 | 3 | 9 | 2 | 8 | 45 | ||
| 9 | 8 | 3 | 4 | 6 | 9 | 2 | 7 | 5 | 1 | 45 | ||
| 45 | 45 | 45 | 45 | 45 | 45 | 45 | 45 | 45 | - All Columns add up to 45; | |||
| 45 | 45 | 45 | - All 3x3 Blocks add up to 45 | |||||||||
| 45 | 45 | 45 | ||||||||||
| 45 | 45 | 45 | ||||||||||
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