| Junior Puzzle #12 - 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 | 4 | 8 | 9 | 2 | 6 | 5 | Junior Puzzle #12 - November 18, 2005 | ||||
| 2 | 9 | 2 | 3 | 5 | 6 | 1 | 8 | 7 | 4 | Original puzzle as published © joe-ks.com | ||
| 3 | 8 | 5 | 7 | 9 | 2 | 1 | ||||||
| 4 | 1 | 7 | 3 | 5 | 6 | 9 | ||||||
| 5 | 4 | 9 | 8 | 6 | 2 | |||||||
| 6 | 3 | 6 | 4 | 9 | 8 | 5 | ||||||
| 7 | 2 | 4 | 1 | 5 | 9 | 8 | ||||||
| 8 | 5 | 3 | 1 | 9 | 2 | 8 | 7 | 4 | 6 | |||
| 9 | 8 | 9 | 4 | 5 | 7 | 3 | 1 | |||||
| A | B | C | D | E | F | G | H | I | ||||
| 1 | 1 | 4 | 8 | 9 | 2 | 6 | 5 | 3 | Step 1: Complete Block CC: #3 MUST go in Cell I1... | |||
| 2 | 9 | 2 | 3 | 5 | 6 | 1 | 8 | 7 | 4 | |||
| 3 | 8 | 5 | 7 | 9 | 2 | 1 | Step 2: #3 is now in Columns G & I: #3 MUST go in Cell H5… | |||||
| 4 | 1 | 7 | 3 | 5 | 6 | 9 | ||||||
| 5 | 4 | 9 | 8 | 6 | 2 | 3 | Step 3: Complete Block II: #2 MUST go in Cell I9... | |||||
| 6 | 3 | 6 | 4 | 9 | 8 | 5 | ||||||
| 7 | 2 | 4 | 1 | 5 | 9 | 8 | ||||||
| 8 | 5 | 3 | 1 | 9 | 2 | 8 | 7 | 4 | 6 | |||
| 9 | 8 | 9 | 4 | 5 | 7 | 3 | 1 | 2 | ||||
| A | B | C | D | E | F | G | H | I | ||||
| 1 | 7 | 1 | 4 | 8 | 9 | 2 | 6 | 5 | 3 | Step 4: Complete Row 1: #7 MUST go in Cell A1... | ||
| 2 | 9 | 2 | 3 | 5 | 6 | 1 | 8 | 7 | 4 | |||
| 3 | 8 | 5 | 7 | 9 | 2 | 1 | Step 5: #7 is now in Columns A & B: #7 MUST go in Cell C7... | |||||
| 4 | 1 | 7 | 3 | 5 | 6 | 9 | ||||||
| 5 | 4 | 9 | 8 | 6 | 2 | 3 | 7 | Step 6: Complete Column I: #7 MUST go in Cell I5... | ||||
| 6 | 3 | 6 | 4 | 9 | 8 | 5 | ||||||
| 7 | 2 | 4 | 7 | 1 | 5 | 9 | 8 | |||||
| 8 | 5 | 3 | 1 | 9 | 2 | 8 | 7 | 4 | 6 | |||
| 9 | 8 | 9 | 4 | 5 | 7 | 3 | 1 | 2 | ||||
| A | B | C | D | E | F | G | H | I | ||||
| 1 | 7 | 1 | 4 | 8 | 9 | 2 | 6 | 5 | 3 | Step 7: Complete Block GG: #6 MUST go in Cell A9... | ||
| 2 | 9 | 2 | 3 | 5 | 6 | 1 | 8 | 7 | 4 | |||
| 3 | 8 | 5 | 6 | 7 | 9 | 2 | 1 | Step 8: #6 is now in Columns A & B: #6 MUST go in Cell C3... | ||||
| 4 | 1 | 7 | 3 | 5 | 6 | 9 | ||||||
| 5 | 4 | 9 | 8 | 6 | 2 | 3 | 7 | |||||
| 6 | 3 | 6 | 4 | 9 | 8 | 5 | ||||||
| 7 | 2 | 4 | 7 | 1 | 5 | 9 | 8 | |||||
| 8 | 5 | 3 | 1 | 9 | 2 | 8 | 7 | 4 | 6 | |||
| 9 | 6 | 8 | 9 | 4 | 5 | 7 | 3 | 1 | 2 | |||
| A | B | C | D | E | F | G | H | I | ||||
| 1 | 7 | 1 | 4 | 8 | 9 | 2 | 6 | 5 | 3 | Step 9: Complete Block BB: need #s 3 & 4… | ||
| 2 | 9 | 2 | 3 | 5 | 6 | 1 | 8 | 7 | 4 | #4 can't go in Cell D3 (cf #4 in Column D @ D9), so | ||
| 3 | 8 | 5 | 6 | 3 | 7 | 4 | 9 | 2 | 1 | #4 MUST go in Cell F3, & therefore #3 MUST go in Cell D3 | ||
| 4 | 1 | 7 | 3 | 5 | 6 | 9 | ||||||
| 5 | 4 | 9 | 8 | 6 | 2 | 3 | 7 | Step 10: #3 is now in Columns D & E: #3 MUST go in Cell F7... | ||||
| 6 | 3 | 6 | 4 | 9 | 8 | 5 | ||||||
| 7 | 2 | 4 | 7 | 1 | 3 | 5 | 9 | 8 | ||||
| 8 | 5 | 3 | 1 | 9 | 2 | 8 | 7 | 4 | 6 | |||
| 9 | 6 | 8 | 9 | 4 | 5 | 7 | 3 | 1 | 2 | |||
| A | B | C | D | E | F | G | H | I | ||||
| 1 | 7 | 1 | 4 | 8 | 9 | 2 | 6 | 5 | 3 | Step 11: Complete Row 7: #6 MUST go in Cell D7… | ||
| 2 | 9 | 2 | 3 | 5 | 6 | 1 | 8 | 7 | 4 | |||
| 3 | 8 | 5 | 6 | 3 | 7 | 4 | 9 | 2 | 1 | Step 12: Complete Block FF: need #s 1 & 4… | ||
| 4 | 1 | 7 | 3 | 5 | 4 | 6 | 9 | #4 can't go in Cell G6 (cf #4 in Row 6 @ E6), so | ||||
| 5 | 4 | 9 | 8 | 6 | 2 | 3 | 7 | #4 MUST go in Cell G4, & therefore #1 MUST go in Cell G6 | ||||
| 6 | 3 | 6 | 4 | 9 | 1 | 8 | 5 | |||||
| 7 | 2 | 4 | 7 | 6 | 1 | 3 | 5 | 9 | 8 | |||
| 8 | 5 | 3 | 1 | 9 | 2 | 8 | 7 | 4 | 6 | |||
| 9 | 6 | 8 | 9 | 4 | 5 | 7 | 3 | 1 | 2 | |||
| A | B | C | D | E | F | G | H | I | ||||
| 1 | 7 | 1 | 4 | 8 | 9 | 2 | 6 | 5 | 3 | Step 13: Complete Row 6: need #s 2 & 7… | ||
| 2 | 9 | 2 | 3 | 5 | 6 | 1 | 8 | 7 | 4 | #7 can't go in Cell C6 (cf #7 in Column C @ C7), so | ||
| 3 | 8 | 5 | 6 | 3 | 7 | 4 | 9 | 2 | 1 | #7 MUST go in Cell D6, & therefore #2 MUST go in Cell C6 | ||
| 4 | 1 | 7 | 8 | 2 | 3 | 5 | 4 | 6 | 9 | |||
| 5 | 4 | 9 | 8 | 6 | 2 | 3 | 7 | Step 14: Complete Row 4: need #s 2 & 8… | ||||
| 6 | 3 | 6 | 2 | 7 | 4 | 9 | 1 | 8 | 5 | #2 can't go in Cell C4 (cf #2 from Step 13 @ C6), so | ||
| 7 | 2 | 4 | 7 | 6 | 1 | 3 | 5 | 9 | 8 | #2 MUST go in Cell D4, & therefore #8 MUST go in Cell C4 | ||
| 8 | 5 | 3 | 1 | 9 | 2 | 8 | 7 | 4 | 6 | |||
| 9 | 6 | 8 | 9 | 4 | 5 | 7 | 3 | 1 | 2 | |||
| A | B | C | D | E | F | G | H | I | ||||
| 1 | 7 | 1 | 4 | 8 | 9 | 2 | 6 | 5 | 3 | Step 15: Complete Block DD: #5 MUST go in Cell C5... | ||
| 2 | 9 | 2 | 3 | 5 | 6 | 1 | 8 | 7 | 4 | |||
| 3 | 8 | 5 | 6 | 3 | 7 | 4 | 9 | 2 | 1 | Step 16: Complete Block EE (& Puzzle): #1 MUST go in Cell D5. | ||
| 4 | 1 | 7 | 8 | 2 | 3 | 5 | 4 | 6 | 9 | |||
| 5 | 4 | 9 | 5 | 1 | 8 | 6 | 2 | 3 | 7 | |||
| 6 | 3 | 6 | 2 | 7 | 4 | 9 | 1 | 8 | 5 | |||
| 7 | 2 | 4 | 7 | 6 | 1 | 3 | 5 | 9 | 8 | |||
| 8 | 5 | 3 | 1 | 9 | 2 | 8 | 7 | 4 | 6 | |||
| 9 | 6 | 8 | 9 | 4 | 5 | 7 | 3 | 1 | 2 | |||
| A | B | C | D | E | F | G | H | I | ||||
| 1 | 7 | 1 | 4 | 8 | 9 | 2 | 6 | 5 | 3 | 45 | Final Proof: | |
| 2 | 9 | 2 | 3 | 5 | 6 | 1 | 8 | 7 | 4 | 45 | - All Rows add up to 45; | |
| 3 | 8 | 5 | 6 | 3 | 7 | 4 | 9 | 2 | 1 | 45 | ||
| 4 | 1 | 7 | 8 | 2 | 3 | 5 | 4 | 6 | 9 | 45 | ||
| 5 | 4 | 9 | 5 | 1 | 8 | 6 | 2 | 3 | 7 | 45 | ||
| 6 | 3 | 6 | 2 | 7 | 4 | 9 | 1 | 8 | 5 | 45 | ||
| 7 | 2 | 4 | 7 | 6 | 1 | 3 | 5 | 9 | 8 | 45 | ||
| 8 | 5 | 3 | 1 | 9 | 2 | 8 | 7 | 4 | 6 | 45 | ||
| 9 | 6 | 8 | 9 | 4 | 5 | 7 | 3 | 1 | 2 | 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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