| Junior Puzzle #15 - 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 | 4 | 5 | 6 | 1 | 7 | 3 | 8 | 2 | Junior Puzzle #15 - November 21, 2005 | ||
| 2 | 2 | 1 | 5 | 8 | 3 | 7 | 6 | Original puzzle as published © joe-ks.com | |||
| 3 | 8 | 3 | 6 | 2 | 4 | 1 | 9 | ||||
| 4 | 4 | 8 | 1 | 6 | 7 | 9 | |||||
| 5 | 9 | 3 | 1 | 4 | 5 | 2 | 6 | 8 | |||
| 6 | 2 | 7 | 8 | 3 | 5 | 1 | |||||
| 7 | 1 | 2 | 3 | 5 | 8 | 6 | 7 | ||||
| 8 | 7 | 6 | 9 | 4 | 2 | 3 | 1 | ||||
| 9 | 3 | 8 | 4 | 7 | 1 | 9 | 2 | 5 | |||
| A | B | C | D | E | F | G | H | I | |||
| 1 | 4 | 5 | 6 | 1 | 9 | 7 | 3 | 8 | 2 | Step 1: Complete Block BB: #9 MUST go in Cell E1... | |
| 2 | 2 | 1 | 9 | 5 | 8 | 3 | 7 | 6 | |||
| 3 | 8 | 3 | 6 | 2 | 4 | 1 | 9 | Step 2: #9 is now in Rows 1 & 3: #9 MUST go in Cell C2... | |||
| 4 | 4 | 8 | 1 | 6 | 7 | 9 | |||||
| 5 | 9 | 3 | 1 | 4 | 5 | 2 | 6 | 8 | Step 3: Complete Row 9: #6 MUST go in Cell E9... | ||
| 6 | 2 | 7 | 8 | 3 | 5 | 1 | |||||
| 7 | 1 | 2 | 3 | 5 | 8 | 6 | 7 | ||||
| 8 | 7 | 6 | 9 | 4 | 2 | 3 | 1 | ||||
| 9 | 3 | 8 | 4 | 7 | 6 | 1 | 9 | 2 | 5 | ||
| A | B | C | D | E | F | G | H | I | |||
| 1 | 4 | 5 | 6 | 1 | 9 | 7 | 3 | 8 | 2 | Step 4: Complete Block AA: #7 MUST go in Cell B3... | |
| 2 | 2 | 1 | 9 | 5 | 8 | 3 | 7 | 6 | |||
| 3 | 8 | 7 | 3 | 6 | 2 | 4 | 1 | 9 | Step 5: Complete Column D: #2 MUST go in Cell D4... | ||
| 4 | 4 | 8 | 2 | 1 | 6 | 7 | 9 | ||||
| 5 | 9 | 3 | 1 | 4 | 7 | 5 | 2 | 6 | 8 | Step 6: Complete Column E: #7 MUST go in Cell E5… | |
| 6 | 2 | 7 | 8 | 3 | 9 | 5 | 1 | ||||
| 7 | 1 | 2 | 3 | 5 | 8 | 6 | 7 | Step 7: Complete Column F: #9 MUST go in Cell F6… | |||
| 8 | 7 | 6 | 9 | 4 | 2 | 3 | 1 | ||||
| 9 | 3 | 8 | 4 | 7 | 6 | 1 | 9 | 2 | 5 | ||
| A | B | C | D | E | F | G | H | I | |||
| 1 | 4 | 5 | 6 | 1 | 9 | 7 | 3 | 8 | 2 | Step 8: Complete Column B: #9 MUST go in Cell B7... | |
| 2 | 2 | 1 | 9 | 5 | 8 | 3 | 7 | 6 | |||
| 3 | 8 | 7 | 3 | 6 | 2 | 4 | 1 | 9 | Step 9: Complete Column C: #5 MUST go in Cell C8... | ||
| 4 | 4 | 8 | 2 | 1 | 6 | 7 | 9 | ||||
| 5 | 9 | 3 | 1 | 4 | 7 | 5 | 2 | 6 | 8 | Step 10: Complete Row 7: #4 MUST go in Cell H7... | |
| 6 | 2 | 7 | 8 | 3 | 9 | 5 | 1 | ||||
| 7 | 1 | 9 | 2 | 3 | 5 | 8 | 6 | 4 | 7 | ||
| 8 | 7 | 6 | 5 | 9 | 4 | 2 | 3 | 1 | |||
| 9 | 3 | 8 | 4 | 7 | 6 | 1 | 9 | 2 | 5 | ||
| A | B | C | D | E | F | G | H | I | |||
| 1 | 4 | 5 | 6 | 1 | 9 | 7 | 3 | 8 | 2 | Step 11: Complete Row 8: #8 MUST go in Cell G8... | |
| 2 | 2 | 1 | 9 | 5 | 8 | 3 | 4 | 7 | 6 | ||
| 3 | 8 | 7 | 3 | 6 | 2 | 4 | 1 | 5 | 9 | Step 12: Complete Column G: #4 MUST go in Cell G2... | |
| 4 | 4 | 8 | 2 | 1 | 6 | 7 | 9 | ||||
| 5 | 9 | 3 | 1 | 4 | 7 | 5 | 2 | 6 | 8 | Step 13: Complete Column H: #5 MUST go in Cell H3... | |
| 6 | 2 | 7 | 8 | 3 | 9 | 5 | 1 | ||||
| 7 | 1 | 9 | 2 | 3 | 5 | 8 | 6 | 4 | 7 | ||
| 8 | 7 | 6 | 5 | 9 | 4 | 2 | 8 | 3 | 1 | ||
| 9 | 3 | 8 | 4 | 7 | 6 | 1 | 9 | 2 | 5 | ||
| A | B | C | D | E | F | G | H | I | |||
| 1 | 4 | 5 | 6 | 1 | 9 | 7 | 3 | 8 | 2 | Step 14: Complete Block DD: need #s 5 & 6… | |
| 2 | 2 | 1 | 9 | 5 | 8 | 3 | 4 | 7 | 6 | #6 can't go in Cell A4 (cf #6 in Row 4 @ F4), so | |
| 3 | 8 | 7 | 3 | 6 | 2 | 4 | 1 | 5 | 9 | #6 MUST go in Cell A6, & therefore #5 MUST go in Cell A4 | |
| 4 | 5 | 4 | 8 | 2 | 1 | 6 | 7 | 9 | |||
| 5 | 9 | 3 | 1 | 4 | 7 | 5 | 2 | 6 | 8 | ||
| 6 | 6 | 2 | 7 | 8 | 3 | 9 | 5 | 1 | |||
| 7 | 1 | 9 | 2 | 3 | 5 | 8 | 6 | 4 | 7 | ||
| 8 | 7 | 6 | 5 | 9 | 4 | 2 | 8 | 3 | 1 | ||
| 9 | 3 | 8 | 4 | 7 | 6 | 1 | 9 | 2 | 5 | ||
| A | B | C | D | E | F | G | H | I | |||
| 1 | 4 | 5 | 6 | 1 | 9 | 7 | 3 | 8 | 2 | Step 15: Complete Block FF (& Puzzle): need #s 3 & 4… | |
| 2 | 2 | 1 | 9 | 5 | 8 | 3 | 4 | 7 | 6 | #3 can't go in Cell I6 (cf #3 in Row 6 @ E6), so | |
| 3 | 8 | 7 | 3 | 6 | 2 | 4 | 1 | 5 | 9 | #3 MUST go in Cell I4, & therefore #4 MUST go in Cell I6 | |
| 4 | 5 | 4 | 8 | 2 | 1 | 6 | 7 | 9 | 3 | ||
| 5 | 9 | 3 | 1 | 4 | 7 | 5 | 2 | 6 | 8 | ||
| 6 | 6 | 2 | 7 | 8 | 3 | 9 | 5 | 1 | 4 | ||
| 7 | 1 | 9 | 2 | 3 | 5 | 8 | 6 | 4 | 7 | ||
| 8 | 7 | 6 | 5 | 9 | 4 | 2 | 8 | 3 | 1 | ||
| 9 | 3 | 8 | 4 | 7 | 6 | 1 | 9 | 2 | 5 | ||
| A | B | C | D | E | F | G | H | I | |||
| 1 | 4 | 5 | 6 | 1 | 9 | 7 | 3 | 8 | 2 | 45 | Final Proof: |
| 2 | 2 | 1 | 9 | 5 | 8 | 3 | 4 | 7 | 6 | 45 | - All Rows add up to 45; |
| 3 | 8 | 7 | 3 | 6 | 2 | 4 | 1 | 5 | 9 | 45 | |
| 4 | 5 | 4 | 8 | 2 | 1 | 6 | 7 | 9 | 3 | 45 | |
| 5 | 9 | 3 | 1 | 4 | 7 | 5 | 2 | 6 | 8 | 45 | |
| 6 | 6 | 2 | 7 | 8 | 3 | 9 | 5 | 1 | 4 | 45 | |
| 7 | 1 | 9 | 2 | 3 | 5 | 8 | 6 | 4 | 7 | 45 | |
| 8 | 7 | 6 | 5 | 9 | 4 | 2 | 8 | 3 | 1 | 45 | |
| 9 | 3 | 8 | 4 | 7 | 6 | 1 | 9 | 2 | 5 | 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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