| Easy Puzzle #30 - One Possible Solution Approach… | ||||||||||||
| NB: There is only one final solution to this Sudoku puzzle… | ||||||||||||
| Rules: Place a number from 1-9 in each empty cell so that each row, each column AND each 3x3 block contains all the numbers from 1-9. | ||||||||||||
| 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 | 8 | 6 | 1 | 2 | 7 | Easy Puzzle #30 - October 30, 2005 | ||||||
| 2 | 2 | 3 | 7 | 6 | Original puzzle as published © joe-ks.com | |||||||
| 3 | 6 | 5 | 9 | 8 | 2 | 3 | ||||||
| 4 | 4 | 5 | ||||||||||
| 5 | 7 | 1 | 9 | 8 | ||||||||
| 6 | 6 | 2 | ||||||||||
| 7 | 4 | 9 | 5 | 6 | 7 | 1 | ||||||
| 8 | 1 | 8 | 4 | 2 | ||||||||
| 9 | 3 | 2 | 9 | 1 | 6 | |||||||
| A | B | C | D | E | F | G | H | I | ||||
| 1 | 8 | 6 | 1 | 2 | 7 | Step 1: #7 is in Rows 1 & 2: #7 MUST go in Cell B3... | ||||||
| 2 | 2 | 3 | 7 | 6 | ||||||||
| 3 | 6 | 7 | 5 | 9 | 8 | 2 | 3 | |||||
| 4 | 4 | 5 | Step 2: #9 is in Rows 7 & 9: #9 MUST go in Cell G8 | |||||||||
| 5 | 7 | 1 | 9 | 8 | (#9 in Column H @ H5 excludes use of Cell H8) | |||||||
| 6 | 6 | 2 | ||||||||||
| 7 | 4 | 9 | 5 | 6 | 7 | 1 | ||||||
| 8 | 1 | 8 | 4 | 9 | 2 | |||||||
| 9 | 3 | 2 | 9 | 1 | 6 | |||||||
| A | B | C | D | E | F | G | H | I | ||||
| 1 | 8 | 6 | 1 | 2 | 7 | 9 | Step 3: #6 is in Columns A & B: #6 MUST go in Cell C8 | |||||
| 2 | 2 | 3 | 7 | 6 | (#6 in Row 9 @ H9 excludes use of Cell C9) | |||||||
| 3 | 6 | 7 | 5 | 9 | 8 | 2 | 3 | |||||
| 4 | 4 | 5 | Step 4: #9 is in Columns G & H: #9 MUST go in Cell I1… | |||||||||
| 5 | 7 | 1 | 9 | 8 | ||||||||
| 6 | 6 | 2 | ||||||||||
| 7 | 4 | 9 | 5 | 6 | 7 | 1 | ||||||
| 8 | 1 | 6 | 8 | 4 | 9 | 2 | ||||||
| 9 | 3 | 2 | 9 | 1 | 6 | |||||||
| A | B | C | D | E | F | G | H | I | ||||
| 1 | 8 | 6 | 1 | 2 | 5 | 7 | 9 | Step 5: Complete Block BB: need #s 4 & 5… | ||||
| 2 | 2 | 3 | 5 | 7 | 6 | #5 can't go in Cell E3 (cf #5 in Row 3 @ C3), so | ||||||
| 3 | 6 | 7 | 5 | 9 | 4 | 8 | 2 | 3 | #5 MUST go in Cell E2, & therefore #4 MUST go in Cell E3 | |||
| 4 | 4 | 5 | ||||||||||
| 5 | 7 | 1 | 9 | 8 | Step 6: #5 is now in Rows 2 & 3: #5 MUST go in Cell G1… | |||||||
| 6 | 6 | 2 | ||||||||||
| 7 | 4 | 9 | 5 | 3 | 6 | 7 | 1 | Step 7: Complete Box HH: need #s 3 & 7… | ||||
| 8 | 1 | 6 | 8 | 7 | 4 | 9 | 2 | #7 can't go in Cell E7 (cf #7 in Row 7 @ G7), so | ||||
| 9 | 3 | 2 | 9 | 1 | 6 | #7 MUST go in Cell E8, & therefore #3 MUST go in Cell E7 | ||||||
| A | B | C | D | E | F | G | H | I | ||||
| 1 | 8 | 6 | 1 | 2 | 5 | 7 | 9 | Step 8: #1 is in Columns A & B: #1 MUST go in Cell C2 | ||||
| 2 | 2 | 1 | 3 | 5 | 7 | 6 | (#1 in Row 1 @ E1 excludes use of Cell C1) | |||||
| 3 | 6 | 7 | 5 | 9 | 4 | 8 | 2 | 1 | 3 | |||
| 4 | 4 | 5 | Step 9: #1 is now in Rows 1 & 2: #1 MUST go in Cell H3... | |||||||||
| 5 | 7 | 1 | 9 | 8 | ||||||||
| 6 | 6 | 2 | Step 10: #2 is in Rows 8 & 9: #2 MUST go in Cell B7... | |||||||||
| 7 | 4 | 2 | 9 | 5 | 3 | 6 | 7 | 1 | ||||
| 8 | 1 | 6 | 8 | 7 | 4 | 9 | 2 | |||||
| 9 | 3 | 2 | 9 | 1 | 6 | |||||||
| A | B | C | D | E | F | G | H | I | ||||
| 1 | 8 | 6 | 1 | 2 | 5 | 7 | 9 | Step 11: #7 is in Columns A & B: #7 MUST go in Cell C9... | ||||
| 2 | 2 | 1 | 3 | 5 | 7 | 6 | ||||||
| 3 | 6 | 7 | 5 | 9 | 4 | 8 | 2 | 1 | 3 | Step 12: #5 is in Columns G & H: #5 MUST go in Cell I9... | ||
| 4 | 4 | 5 | ||||||||||
| 5 | 7 | 1 | 9 | 8 | Step 13: #5 is now in Rows 7 & 9: #5 MUST go in Cell B8,,, | |||||||
| 6 | 6 | 2 | ||||||||||
| 7 | 4 | 2 | 9 | 5 | 3 | 6 | 7 | 1 | ||||
| 8 | 1 | 5 | 6 | 8 | 7 | 4 | 9 | 2 | ||||
| 9 | 3 | 7 | 2 | 9 | 1 | 6 | 5 | |||||
| A | B | C | D | E | F | G | H | I | ||||
| 1 | 8 | 6 | 1 | 2 | 5 | 7 | 9 | Step 14: Complete Block GG: #8 MUST go in Cell A9... | ||||
| 2 | 2 | 1 | 3 | 5 | 7 | 8 | 4 | 6 | ||||
| 3 | 6 | 7 | 5 | 9 | 4 | 8 | 2 | 1 | 3 | Step 15: #8 is now in Rows 8 & 9: #8 MUST go in Cell H7... | ||
| 4 | 4 | 5 | ||||||||||
| 5 | 7 | 1 | 9 | 8 | Step 16: #8 is now in Columns H & I: #8 MUST go in Cell G2 | |||||||
| 6 | 6 | 2 | ||||||||||
| 7 | 4 | 2 | 9 | 5 | 3 | 6 | 7 | 8 | 1 | Step 17: Complete Block CC: #4 MUST go in Cell H2... | ||
| 8 | 1 | 5 | 6 | 8 | 7 | 4 | 9 | 2 | ||||
| 9 | 8 | 3 | 7 | 2 | 9 | 1 | 6 | 5 | ||||
| A | B | C | D | E | F | G | H | I | ||||
| 1 | 8 | 6 | 1 | 2 | 5 | 7 | 9 | Step 18: Complete Column B: #9 MUST go in Cell B2... | ||||
| 2 | 2 | 9 | 1 | 3 | 5 | 7 | 8 | 4 | 6 | |||
| 3 | 6 | 7 | 5 | 9 | 4 | 8 | 2 | 1 | 3 | Step 19: Complete Column H: #3 MUST go in Cell H8... | ||
| 4 | 4 | 5 | ||||||||||
| 5 | 7 | 1 | 9 | 8 | ||||||||
| 6 | 6 | 2 | ||||||||||
| 7 | 4 | 2 | 9 | 5 | 3 | 6 | 7 | 8 | 1 | |||
| 8 | 1 | 5 | 6 | 8 | 7 | 4 | 9 | 3 | 2 | |||
| 9 | 8 | 3 | 7 | 2 | 9 | 1 | 6 | 5 | ||||
| A | B | C | D | E | F | G | H | I | ||||
| 1 | 3 | 8 | 4 | 6 | 1 | 2 | 5 | 7 | 9 | Step 20: Complete Column I: need #s 4 & 7… | ||
| 2 | 2 | 9 | 1 | 3 | 5 | 7 | 8 | 4 | 6 | #4 can't go in Cell I4 (cf #4 in Row 4 @ B4), so | ||
| 3 | 6 | 7 | 5 | 9 | 4 | 8 | 2 | 1 | 3 | #4 MUST go in Cell I6, & therefore #7 MUST go in Cell I4 | ||
| 4 | 4 | 5 | 7 | |||||||||
| 5 | 7 | 1 | 9 | 8 | Step 21: Complete Block AA: need #s 3 & 4… | |||||||
| 6 | 6 | 2 | 4 | #4 can't go in Cell A1 (cf #4 in Column A @ A7), so | ||||||||
| 7 | 4 | 2 | 9 | 5 | 3 | 6 | 7 | 8 | 1 | #4 MUST go in Cell C1, & therefore #3 MUST go in Cell A1 | ||
| 8 | 1 | 5 | 6 | 8 | 7 | 4 | 9 | 3 | 2 | |||
| 9 | 8 | 3 | 7 | 2 | 9 | 1 | 6 | 5 | ||||
| A | B | C | D | E | F | G | H | I | ||||
| 1 | 3 | 8 | 4 | 6 | 1 | 2 | 5 | 7 | 9 | Step 22: Complete Column A: need #s 5 & 9… | ||
| 2 | 2 | 9 | 1 | 3 | 5 | 7 | 8 | 4 | 6 | #5 can't go in Cell A4 (cf #5 in Row 4 @ H4), so | ||
| 3 | 6 | 7 | 5 | 9 | 4 | 8 | 2 | 1 | 3 | #5 MUST go in Cell A6, & therefore #9 MUST go in Cell A4 | ||
| 4 | 9 | 4 | 5 | 7 | ||||||||
| 5 | 7 | 1 | 9 | 8 | ||||||||
| 6 | 5 | 6 | 2 | 4 | ||||||||
| 7 | 4 | 2 | 9 | 5 | 3 | 6 | 7 | 8 | 1 | |||
| 8 | 1 | 5 | 6 | 8 | 7 | 4 | 9 | 3 | 2 | |||
| 9 | 8 | 3 | 7 | 2 | 9 | 1 | 6 | 5 | ||||
| A | B | C | D | E | F | G | H | I | ||||
| 1 | 3 | 8 | 4 | 6 | 1 | 2 | 5 | 7 | 9 | Step 23: Block EE needs #4: #4 MUST go in Cell D5 | ||
| 2 | 2 | 9 | 1 | 3 | 5 | 7 | 8 | 4 | 6 | (#4 in Row 4 @ B4 excludes use of Cells D4, E4 & F4; | ||
| 3 | 6 | 7 | 5 | 9 | 4 | 8 | 2 | 1 | 3 | #4 in Row 6 @ I6 excludes use of Cells D6, E6 & F6; | ||
| 4 | 9 | 4 | 5 | 7 | #4 in Column E @ E4 further exludes Cell E5, & | |||||||
| 5 | 7 | 1 | 4 | 9 | 8 | #4 in Column F @ F8 further excludes Cell F5) | ||||||
| 6 | 5 | 6 | 2 | 4 | ||||||||
| 7 | 4 | 2 | 9 | 5 | 3 | 6 | 7 | 8 | 1 | |||
| 8 | 1 | 5 | 6 | 8 | 7 | 4 | 9 | 3 | 2 | |||
| 9 | 8 | 3 | 7 | 2 | 9 | 1 | 6 | 5 | ||||
| A | B | C | D | E | F | G | H | I | ||||
| 1 | 3 | 8 | 4 | 6 | 1 | 2 | 5 | 7 | 9 | Step 24: Block EE needs #7: #7 MUST go in Cell D6 | ||
| 2 | 2 | 9 | 1 | 3 | 5 | 7 | 8 | 4 | 6 | (cf excluded Cells from #7's in Rows 4&5 & Columns E&F) | ||
| 3 | 6 | 7 | 5 | 9 | 4 | 8 | 2 | 1 | 3 | |||
| 4 | 9 | 4 | 5 | 7 | ||||||||
| 5 | 7 | 1 | 4 | 9 | 8 | |||||||
| 6 | 5 | 6 | 7 | 2 | 4 | |||||||
| 7 | 4 | 2 | 9 | 5 | 3 | 6 | 7 | 8 | 1 | |||
| 8 | 1 | 5 | 6 | 8 | 7 | 4 | 9 | 3 | 2 | |||
| 9 | 8 | 3 | 7 | 2 | 9 | 1 | 6 | 5 | ||||
| A | B | C | D | E | F | G | H | I | ||||
| 1 | 3 | 8 | 4 | 6 | 1 | 2 | 5 | 7 | 9 | Step 25: Block EE needs #5: #5 MUST go in Cell F5 | ||
| 2 | 2 | 9 | 1 | 3 | 5 | 7 | 8 | 4 | 6 | (cf excluded Cells from #5's in Rows 4&6 & Columns D&E) | ||
| 3 | 6 | 7 | 5 | 9 | 4 | 8 | 2 | 1 | 3 | |||
| 4 | 9 | 4 | 5 | 7 | ||||||||
| 5 | 7 | 1 | 4 | 5 | 9 | 8 | ||||||
| 6 | 5 | 6 | 7 | 2 | 4 | |||||||
| 7 | 4 | 2 | 9 | 5 | 3 | 6 | 7 | 8 | 1 | |||
| 8 | 1 | 5 | 6 | 8 | 7 | 4 | 9 | 3 | 2 | |||
| 9 | 8 | 3 | 7 | 2 | 9 | 1 | 6 | 5 | ||||
| A | B | C | D | E | F | G | H | I | ||||
| 1 | 3 | 8 | 4 | 6 | 1 | 2 | 5 | 7 | 9 | Step 26: Block EE needs #9: #9 MUST go in Cell F6 | ||
| 2 | 2 | 9 | 1 | 3 | 5 | 7 | 8 | 4 | 6 | (cf excluded Cells from #9's in Rows 4&5 & Columns D&E) | ||
| 3 | 6 | 7 | 5 | 9 | 4 | 8 | 2 | 1 | 3 | |||
| 4 | 9 | 4 | 5 | 7 | ||||||||
| 5 | 7 | 1 | 4 | 5 | 9 | 8 | ||||||
| 6 | 5 | 6 | 7 | 9 | 2 | 4 | ||||||
| 7 | 4 | 2 | 9 | 5 | 3 | 6 | 7 | 8 | 1 | |||
| 8 | 1 | 5 | 6 | 8 | 7 | 4 | 9 | 3 | 2 | |||
| 9 | 8 | 3 | 7 | 2 | 9 | 1 | 6 | 5 | ||||
| A | B | C | D | E | F | G | H | I | ||||
| 1 | 3 | 8 | 4 | 6 | 1 | 2 | 5 | 7 | 9 | Step 27: Complete Column D: #1 MUST go in Cell D4... | ||
| 2 | 2 | 9 | 1 | 3 | 5 | 7 | 8 | 4 | 6 | |||
| 3 | 6 | 7 | 5 | 9 | 4 | 8 | 2 | 1 | 3 | Step 28: #1 is now in Rows 4 & 5: #1 MUST go in Cell G6... | ||
| 4 | 9 | 4 | 1 | 3 | 5 | 7 | ||||||
| 5 | 7 | 1 | 4 | 5 | 9 | 8 | Step 29: Complete Column F: #3 MUST go in Cell F4... | |||||
| 6 | 5 | 6 | 7 | 9 | 1 | 2 | 4 | |||||
| 7 | 4 | 2 | 9 | 5 | 3 | 6 | 7 | 8 | 1 | Step 30: Complete Row 9: #4 MUST go in Cell G9... | ||
| 8 | 1 | 5 | 6 | 8 | 7 | 4 | 9 | 3 | 2 | |||
| 9 | 8 | 3 | 7 | 2 | 9 | 1 | 4 | 6 | 5 | |||
| A | B | C | D | E | F | G | H | I | ||||
| 1 | 3 | 8 | 4 | 6 | 1 | 2 | 5 | 7 | 9 | Step 31: Complete Block FF: need #s 3 & 6… | ||
| 2 | 2 | 9 | 1 | 3 | 5 | 7 | 8 | 4 | 6 | #3 can't go in Cell G4 (cf #3 in Row 4 @ F4), so | ||
| 3 | 6 | 7 | 5 | 9 | 4 | 8 | 2 | 1 | 3 | #3 MUST go in Cell G5, & therefore #6 MUST go in Cell G4 | ||
| 4 | 9 | 4 | 1 | 3 | 6 | 5 | 7 | |||||
| 5 | 7 | 1 | 4 | 5 | 3 | 9 | 8 | |||||
| 6 | 5 | 6 | 7 | 9 | 1 | 2 | 4 | |||||
| 7 | 4 | 2 | 9 | 5 | 3 | 6 | 7 | 8 | 1 | |||
| 8 | 1 | 5 | 6 | 8 | 7 | 4 | 9 | 3 | 2 | |||
| 9 | 8 | 3 | 7 | 2 | 9 | 1 | 4 | 6 | 5 | |||
| A | B | C | D | E | F | G | H | I | ||||
| 1 | 3 | 8 | 4 | 6 | 1 | 2 | 5 | 7 | 9 | Step 32: Complete Row 6: need #s 3 & 8… | ||
| 2 | 2 | 9 | 1 | 3 | 5 | 7 | 8 | 4 | 6 | #3 can't go in Cell E6 (cf #3 in Column E @ E7), so | ||
| 3 | 6 | 7 | 5 | 9 | 4 | 8 | 2 | 1 | 3 | #3 MUST go in Cell C6, & therefore #8 MUST go in Cell E6 | ||
| 4 | 9 | 4 | 8 | 1 | 2 | 3 | 6 | 5 | 7 | |||
| 5 | 7 | 1 | 4 | 5 | 3 | 9 | 8 | Step 33: Complete Row 4: need #s 2 & 8… | ||||
| 6 | 5 | 6 | 3 | 7 | 8 | 9 | 1 | 2 | 4 | #8 can't go in Cell E4 (cf #8 from Step 32 @ E6), so | ||
| 7 | 4 | 2 | 9 | 5 | 3 | 6 | 7 | 8 | 1 | #8 MUST go in Cell C4, & therefore #2 MUST go in Cell E4 | ||
| 8 | 1 | 5 | 6 | 8 | 7 | 4 | 9 | 3 | 2 | |||
| 9 | 8 | 3 | 7 | 2 | 9 | 1 | 4 | 6 | 5 | |||
| A | B | C | D | E | F | G | H | I | ||||
| 1 | 3 | 8 | 4 | 6 | 1 | 2 | 5 | 7 | 9 | Step 34: Complete Row 5 (& Puzzle): need #s 2 & 6… | ||
| 2 | 2 | 9 | 1 | 3 | 5 | 7 | 8 | 4 | 6 | #2 can’t go in Cell E5 (cf #2 in Column E @ E4), so | ||
| 3 | 6 | 7 | 5 | 9 | 4 | 8 | 2 | 1 | 3 | #2 MUST go in Cell C5, & therefore #6 MUST go in Cell E5. | ||
| 4 | 9 | 4 | 8 | 1 | 2 | 3 | 6 | 5 | 7 | |||
| 5 | 7 | 1 | 2 | 4 | 6 | 5 | 3 | 9 | 8 | |||
| 6 | 5 | 6 | 3 | 7 | 8 | 9 | 1 | 2 | 4 | |||
| 7 | 4 | 2 | 9 | 5 | 3 | 6 | 7 | 8 | 1 | |||
| 8 | 1 | 5 | 6 | 8 | 7 | 4 | 9 | 3 | 2 | |||
| 9 | 8 | 3 | 7 | 2 | 9 | 1 | 4 | 6 | 5 | |||
| A | B | C | D | E | F | G | H | I | ||||
| 1 | 3 | 8 | 4 | 6 | 1 | 2 | 5 | 7 | 9 | 45 | Final Proof: | |
| 2 | 2 | 9 | 1 | 3 | 5 | 7 | 8 | 4 | 6 | 45 | - All Rows add up to 45; | |
| 3 | 6 | 7 | 5 | 9 | 4 | 8 | 2 | 1 | 3 | 45 | ||
| 4 | 9 | 4 | 8 | 1 | 2 | 3 | 6 | 5 | 7 | 45 | ||
| 5 | 7 | 1 | 2 | 4 | 6 | 5 | 3 | 9 | 8 | 45 | ||
| 6 | 5 | 6 | 3 | 7 | 8 | 9 | 1 | 2 | 4 | 45 | ||
| 7 | 4 | 2 | 9 | 5 | 3 | 6 | 7 | 8 | 1 | 45 | ||
| 8 | 1 | 5 | 6 | 8 | 7 | 4 | 9 | 3 | 2 | 45 | ||
| 9 | 8 | 3 | 7 | 2 | 9 | 1 | 4 | 6 | 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 | ||||||||||
Send your Comments to joe-ks.com