| Easy Puzzle #19 - 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 | 2 | 8 | 5 | Easy Puzzle #19 - October 19, 2005 | ||||||||
| 2 | 4 | 3 | 1 | 7 | 9 | 2 | 6 | Original puzzle as published on joe-ks.com… | ||||
| 3 | 9 | 3 | 8 | 4 | 1 | |||||||
| 4 | 7 | 1 | 5 | 9 | ||||||||
| 5 | 6 | 5 | 8 | 9 | 7 | 4 | ||||||
| 6 | 3 | 4 | 2 | |||||||||
| 7 | 7 | 6 | 4 | |||||||||
| 8 | 2 | 4 | 5 | 1 | 7 | |||||||
| 9 | 9 | 1 | 2 | 6 | 3 | |||||||
| A | B | C | D | E | F | G | H | I | ||||
| 1 | 2 | 8 | 5 | Step 1: Complete Column F: #3 MUST go in Cell F7… | ||||||||
| 2 | 4 | 3 | 1 | 7 | 9 | 2 | 6 | |||||
| 3 | 9 | 3 | 8 | 4 | 7 | 1 | Step 2: #3 is in Columns B & C: #3 MUST go in Cell A8 | |||||
| 4 | 7 | 1 | 5 | 9 | (cf #3 from Step 1 excludes use of Cell A7) | |||||||
| 5 | 6 | 5 | 8 | 9 | 7 | 4 | ||||||
| 6 | 3 | 4 | 2 | Step 3: #7 is in Columns G & I: #7 MUST go in Cell H3… | ||||||||
| 7 | 7 | 6 | 4 | 3 | ||||||||
| 8 | 3 | 2 | 4 | 5 | 1 | 7 | ||||||
| 9 | 9 | 1 | 2 | 6 | 3 | |||||||
| A | B | C | D | E | F | G | H | I | ||||
| 1 | 2 | 3 | 8 | 5 | Step 4: Complete Block CC: #3 MUST go in Cell G1… | |||||||
| 2 | 4 | 3 | 1 | 7 | 9 | 2 | 6 | |||||
| 3 | 9 | 3 | 8 | 4 | 7 | 1 | ||||||
| 4 | 7 | 4 | 1 | 5 | 9 | Step 5: #4 is in Rows 5 & 6: #4 MUST go in Cell B4 | ||||||
| 5 | 6 | 5 | 8 | 9 | 7 | 4 | (cf #4 in Column C @ C8 excludes use of Cell C4) | |||||
| 6 | 3 | 4 | 2 | |||||||||
| 7 | 7 | 6 | 4 | 3 | ||||||||
| 8 | 3 | 2 | 4 | 5 | 1 | 7 | ||||||
| 9 | 9 | 1 | 2 | 6 | 3 | |||||||
| A | B | C | D | E | F | G | H | I | ||||
| 1 | 2 | 3 | 8 | 5 | Step 6: #8 is in Rows 1 & 3: #8 MUST go in Cell C2… | |||||||
| 2 | 4 | 3 | 8 | 1 | 7 | 9 | 2 | 6 | ||||
| 3 | 9 | 3 | 8 | 4 | 7 | 1 | ||||||
| 4 | 7 | 4 | 1 | 5 | 9 | Step 7: #9 is in Rows 4 & 5: #9 MUST go in Cell B6 | ||||||
| 5 | 6 | 5 | 8 | 9 | 7 | 4 | (#9 in Column A @ A9 excludes Cell A6) | |||||
| 6 | 9 | 3 | 4 | 2 | ||||||||
| 7 | 7 | 6 | 4 | 3 | ||||||||
| 8 | 3 | 2 | 4 | 5 | 1 | 7 | ||||||
| 9 | 9 | 1 | 2 | 6 | 3 | |||||||
| A | B | C | D | E | F | G | H | I | ||||
| 1 | 2 | 3 | 8 | 5 | Step 8: Complete Row 2: #5 MUST go in Cell D2… | |||||||
| 2 | 4 | 3 | 8 | 5 | 1 | 7 | 9 | 2 | 6 | |||
| 3 | 9 | 3 | 8 | 4 | 7 | 1 | ||||||
| 4 | 7 | 4 | 1 | 5 | 9 | Step 9: Block EE needs #2: #2 MUST go in Cell D5 | ||||||
| 5 | 6 | 5 | 2 | 8 | 9 | 7 | 4 | (#2 in Row 6 @ I6 excludes use of Cells D6 & E6, & | ||||
| 6 | 9 | 3 | 4 | 2 | #2 in Column E @ E9 exlcudes use of Cell E4) | |||||||
| 7 | 7 | 6 | 4 | 3 | ||||||||
| 8 | 3 | 2 | 4 | 5 | 1 | 7 | ||||||
| 9 | 9 | 1 | 2 | 6 | 3 | |||||||
| A | B | C | D | E | F | G | H | I | ||||
| 1 | 2 | 3 | 8 | 5 | Step 10: Complete Row 5: need #s 1 & 3… | |||||||
| 2 | 4 | 3 | 8 | 5 | 1 | 7 | 9 | 2 | 6 | #3 can’t go in Cell A5 (cf #3 in Column A @ A3), so | ||
| 3 | 9 | 3 | 8 | 4 | 7 | 1 | #3 MUST go in Cell H5, & therefore #1 MUST go in Cell A5 | |||||
| 4 | 7 | 4 | 1 | 5 | 9 | |||||||
| 5 | 1 | 6 | 5 | 2 | 8 | 9 | 7 | 3 | 4 | |||
| 6 | 9 | 3 | 4 | 2 | ||||||||
| 7 | 7 | 6 | 4 | 3 | ||||||||
| 8 | 3 | 2 | 4 | 5 | 1 | 7 | ||||||
| 9 | 9 | 1 | 2 | 6 | 3 | |||||||
| A | B | C | D | E | F | G | H | I | ||||
| 1 | 7 | 2 | 3 | 8 | 5 | Step 11: Complete Column C: need #s 2 & 7… | ||||||
| 2 | 4 | 3 | 8 | 5 | 1 | 7 | 9 | 2 | 6 | #2 can't go in Cell C1 (cf #2 in Row 1 @ F1), so | ||
| 3 | 9 | 3 | 8 | 4 | 7 | 1 | #2 MUST go in Cell C4, & therefore #7 MUST go in Cell C1 | |||||
| 4 | 7 | 4 | 2 | 1 | 5 | 9 | ||||||
| 5 | 1 | 6 | 5 | 2 | 8 | 9 | 7 | 3 | 4 | Step 12: #4 is in Columns G & I: #4 MUST go in Cell H9 | ||
| 6 | 9 | 3 | 4 | 2 | (cf #4 in Row 7 @ E7 excludes Cell H7, & #4 in Row 8 | |||||||
| 7 | 7 | 6 | 4 | 3 | @ C8 excludes Cell H8) | |||||||
| 8 | 3 | 2 | 4 | 5 | 1 | 7 | ||||||
| 9 | 9 | 1 | 2 | 6 | 4 | 3 | ||||||
| A | B | C | D | E | F | G | H | I | ||||
| 1 | 1 | 7 | 2 | 3 | 8 | 5 | Step 13: #1 is in Columns A & C: #1 MUST go in Cell B1 | |||||
| 2 | 4 | 3 | 8 | 5 | 1 | 7 | 9 | 2 | 6 | (cf #1 in Row 3 @ I3 excludes use of Cell B3) | ||
| 3 | 9 | 3 | 8 | 4 | 7 | 1 | ||||||
| 4 | 7 | 4 | 2 | 1 | 5 | 9 | ||||||
| 5 | 1 | 6 | 5 | 2 | 8 | 9 | 7 | 3 | 4 | |||
| 6 | 9 | 3 | 4 | 2 | ||||||||
| 7 | 7 | 6 | 4 | 3 | ||||||||
| 8 | 3 | 2 | 4 | 5 | 1 | 7 | ||||||
| 9 | 9 | 1 | 2 | 6 | 4 | 3 | ||||||
| A | B | C | D | E | F | G | H | I | ||||
| 1 | 1 | 7 | 2 | 3 | 8 | 5 | Step 14: #2 is in Rows 1 & 2: #2 MUST go in Cell A3 | |||||
| 2 | 4 | 3 | 8 | 5 | 1 | 7 | 9 | 2 | 6 | (#3 in Column B @ B8 excludes B3) | ||
| 3 | 2 | 9 | 3 | 8 | 4 | 7 | 1 | |||||
| 4 | 7 | 4 | 2 | 1 | 5 | 9 | ||||||
| 5 | 1 | 6 | 5 | 2 | 8 | 9 | 7 | 3 | 4 | |||
| 6 | 9 | 3 | 4 | 2 | ||||||||
| 7 | 7 | 6 | 4 | 3 | ||||||||
| 8 | 3 | 2 | 4 | 5 | 1 | 7 | ||||||
| 9 | 9 | 1 | 2 | 6 | 4 | 3 | ||||||
| A | B | C | D | E | F | G | H | I | ||||
| 1 | 6 | 1 | 7 | 2 | 3 | 8 | 5 | Step 15: Complete Block AA: need #s 5 & 6… | ||||
| 2 | 4 | 3 | 8 | 5 | 1 | 7 | 9 | 2 | 6 | #6 can't go in Cell B3 (cf #6 is in Column B @ B5), so | ||
| 3 | 2 | 5 | 9 | 3 | 8 | 4 | 7 | 1 | #6 MUST go in Cell A1, & therefore #5 MUST go in Cell B3 | |||
| 4 | 7 | 4 | 2 | 1 | 3 | 5 | 9 | |||||
| 5 | 1 | 6 | 5 | 2 | 8 | 9 | 7 | 3 | 4 | Step 16: #3 is in Columns D & F: #3 MUST go in Cell E4 | ||
| 6 | 9 | 3 | 4 | 2 | (cf #3 in Row 6 @ C6 excludes use of Cell E6) | |||||||
| 7 | 7 | 6 | 4 | 3 | ||||||||
| 8 | 3 | 2 | 4 | 5 | 1 | 7 | ||||||
| 9 | 9 | 1 | 2 | 6 | 4 | 3 | ||||||
| A | B | C | D | E | F | G | H | I | ||||
| 1 | 6 | 1 | 7 | 2 | 3 | 8 | 5 | Step 17: Complete Column B: #8 MUST go in Cell B9… | ||||
| 2 | 4 | 3 | 8 | 5 | 1 | 7 | 9 | 2 | 6 | |||
| 3 | 2 | 5 | 9 | 3 | 8 | 4 | 7 | 1 | Step 18: Now #8 is in Columns B & C: #8 MUST go in Cell A6 | |||
| 4 | 7 | 4 | 2 | 1 | 3 | 5 | 9 | |||||
| 5 | 1 | 6 | 5 | 2 | 8 | 9 | 7 | 3 | 4 | |||
| 6 | 8 | 9 | 3 | 4 | 2 | |||||||
| 7 | 7 | 6 | 4 | 3 | ||||||||
| 8 | 3 | 2 | 4 | 5 | 1 | 7 | ||||||
| 9 | 9 | 8 | 1 | 2 | 6 | 4 | 3 | |||||
| A | B | C | D | E | F | G | H | I | ||||
| 1 | 6 | 1 | 7 | 2 | 3 | 8 | 5 | Step 19: Complete Block GG (& Column A): | ||||
| 2 | 4 | 3 | 8 | 5 | 1 | 7 | 9 | 2 | 6 | #5 MUST go in Cell A7… | ||
| 3 | 2 | 5 | 9 | 3 | 6 | 8 | 4 | 7 | 1 | |||
| 4 | 7 | 4 | 2 | 1 | 3 | 5 | 9 | Step 20: #6 is in Rows 1 & 2: #6 MUST go in Cell E3… | ||||
| 5 | 1 | 6 | 5 | 2 | 8 | 9 | 7 | 3 | 4 | |||
| 6 | 8 | 9 | 3 | 4 | 2 | |||||||
| 7 | 5 | 7 | 6 | 4 | 3 | |||||||
| 8 | 3 | 2 | 4 | 5 | 1 | 7 | ||||||
| 9 | 9 | 8 | 1 | 2 | 6 | 4 | 3 | |||||
| A | B | C | D | E | F | G | H | I | ||||
| 1 | 6 | 1 | 7 | 4 | 9 | 2 | 3 | 8 | 5 | Step 21: Complete Row 1 (& Block BB): need #s 4 & 9… | ||
| 2 | 4 | 3 | 8 | 5 | 1 | 7 | 9 | 2 | 6 | #4 can't go in Cell E1 (cf #4 in Column E @ E7), so | ||
| 3 | 2 | 5 | 9 | 3 | 6 | 8 | 4 | 7 | 1 | #4 MUST go in Cell D1, & therefore #9 MUST go in Cell E1 | ||
| 4 | 7 | 4 | 2 | 1 | 3 | 5 | 6 | 9 | 8 | Step 22: Complete Row 4: need #s 6 & 8… | ||
| 5 | 1 | 6 | 5 | 2 | 8 | 9 | 7 | 3 | 4 | #6 can't go in Cell I4 (cf #6 in Column I @ I4), so | ||
| 6 | 8 | 9 | 3 | 4 | 2 | #6 MUST go in Cell G4, & therefore #8 MUST go in Cell I4 | ||||||
| 7 | 5 | 7 | 6 | 4 | 3 | Step 23: Complete Row 9: need #s 5 & 7… | ||||||
| 8 | 3 | 2 | 4 | 5 | 1 | 7 | #7 can't go in Cell G9 (cf #7 in Column G @ G5), so | |||||
| 9 | 9 | 8 | 1 | 7 | 2 | 6 | 5 | 4 | 3 | #7 MUST go in Cell D9, & therefore #5 MUST go in Cell G9 | ||
| A | B | C | D | E | F | G | H | I | ||||
| 1 | 6 | 1 | 7 | 4 | 9 | 2 | 3 | 8 | 5 | Step 24: Complete Column E: #7 MUST go in Cell E6… | ||
| 2 | 4 | 3 | 8 | 5 | 1 | 7 | 9 | 2 | 6 | |||
| 3 | 2 | 5 | 9 | 3 | 6 | 8 | 4 | 7 | 1 | |||
| 4 | 7 | 4 | 2 | 1 | 3 | 5 | 6 | 9 | 8 | Step 25: Complete Block FF: need #s 1 & 5… | ||
| 5 | 1 | 6 | 5 | 2 | 8 | 9 | 7 | 3 | 4 | #5 can't go in Cell G6 (cf #5 in Column G @ G9), so | ||
| 6 | 8 | 9 | 3 | 7 | 4 | 1 | 5 | 2 | #5 MUST go in Cell H6, & therefore #1 MUST go in Cell G6 | |||
| 7 | 5 | 7 | 6 | 4 | 3 | |||||||
| 8 | 3 | 2 | 4 | 5 | 1 | 7 | ||||||
| 9 | 9 | 8 | 1 | 7 | 2 | 6 | 5 | 4 | 3 | |||
| A | B | C | D | E | F | G | H | I | ||||
| 1 | 6 | 1 | 7 | 4 | 9 | 2 | 3 | 8 | 5 | Step 26: Complete Row 6: #6 MUST go in Cell D6… | ||
| 2 | 4 | 3 | 8 | 5 | 1 | 7 | 9 | 2 | 6 | |||
| 3 | 2 | 5 | 9 | 3 | 6 | 8 | 4 | 7 | 1 | |||
| 4 | 7 | 4 | 2 | 1 | 3 | 5 | 6 | 9 | 8 | Step 27: Complete Column G: need #s 2 & 8… | ||
| 5 | 1 | 6 | 5 | 2 | 8 | 9 | 7 | 3 | 4 | #2 can't go in Cell G8 (cf #2 in Row 8 @ B8), so | ||
| 6 | 8 | 9 | 3 | 6 | 7 | 4 | 1 | 5 | 2 | #2 MUST go in Cell G7, & therefore #8 MUST go in Cell G8 | ||
| 7 | 5 | 7 | 6 | 4 | 3 | 2 | ||||||
| 8 | 3 | 2 | 4 | 5 | 1 | 8 | 7 | |||||
| 9 | 9 | 8 | 1 | 7 | 2 | 6 | 5 | 4 | 3 | |||
| A | B | C | D | E | F | G | H | I | ||||
| 1 | 6 | 1 | 7 | 4 | 9 | 2 | 3 | 8 | 5 | Step 28: Complete Column H: need #s 1 & 6… | ||
| 2 | 4 | 3 | 8 | 5 | 1 | 7 | 9 | 2 | 6 | #1 can't go in Cell H8 (cf #1 in Row 8 @ F8), so | ||
| 3 | 2 | 5 | 9 | 3 | 6 | 8 | 4 | 7 | 1 | #1 MUST go in Cell H7, & therefore #6 MUST go in Cell H8 | ||
| 4 | 7 | 4 | 2 | 1 | 3 | 5 | 6 | 9 | 8 | |||
| 5 | 1 | 6 | 5 | 2 | 8 | 9 | 7 | 3 | 4 | |||
| 6 | 8 | 9 | 3 | 6 | 7 | 4 | 1 | 5 | 2 | |||
| 7 | 5 | 7 | 6 | 4 | 3 | 2 | 1 | |||||
| 8 | 3 | 2 | 4 | 5 | 1 | 8 | 6 | 7 | ||||
| 9 | 9 | 8 | 1 | 7 | 2 | 6 | 5 | 4 | 3 | |||
| A | B | C | D | E | F | G | H | I | ||||
| 1 | 6 | 1 | 7 | 4 | 9 | 2 | 3 | 8 | 5 | Step 29: Complete Block II: #9 MUST go in Cell I7… | ||
| 2 | 4 | 3 | 8 | 5 | 1 | 7 | 9 | 2 | 6 | |||
| 3 | 2 | 5 | 9 | 3 | 6 | 8 | 4 | 7 | 1 | |||
| 4 | 7 | 4 | 2 | 1 | 3 | 5 | 6 | 9 | 8 | |||
| 5 | 1 | 6 | 5 | 2 | 8 | 9 | 7 | 3 | 4 | |||
| 6 | 8 | 9 | 3 | 6 | 7 | 4 | 1 | 5 | 2 | |||
| 7 | 5 | 7 | 6 | 4 | 3 | 2 | 1 | 9 | ||||
| 8 | 3 | 2 | 4 | 5 | 1 | 8 | 6 | 7 | ||||
| 9 | 9 | 8 | 1 | 7 | 2 | 6 | 5 | 4 | 3 | |||
| A | B | C | D | E | F | G | H | I | ||||
| 1 | 6 | 1 | 7 | 4 | 9 | 2 | 3 | 8 | 5 | Step 30: Complete Row 7: #8 MUST go in Cell D7… | ||
| 2 | 4 | 3 | 8 | 5 | 1 | 7 | 9 | 2 | 6 | |||
| 3 | 2 | 5 | 9 | 3 | 6 | 8 | 4 | 7 | 1 | Step 31: Complete Row 8 (& Block HH & puzzle): | ||
| 4 | 7 | 4 | 2 | 1 | 3 | 5 | 6 | 9 | 8 | #9 MUST go in Cell D8. | ||
| 5 | 1 | 6 | 5 | 2 | 8 | 9 | 7 | 3 | 4 | |||
| 6 | 8 | 9 | 3 | 6 | 7 | 4 | 1 | 5 | 2 | |||
| 7 | 5 | 7 | 6 | 8 | 4 | 3 | 2 | 1 | 9 | |||
| 8 | 3 | 2 | 4 | 9 | 5 | 1 | 8 | 6 | 7 | |||
| 9 | 9 | 8 | 1 | 7 | 2 | 6 | 5 | 4 | 3 | |||
| A | B | C | D | E | F | G | H | I | ||||
| 1 | 6 | 1 | 7 | 4 | 9 | 2 | 3 | 8 | 5 | 45 | Final Proof: | |
| 2 | 4 | 3 | 8 | 5 | 1 | 7 | 9 | 2 | 6 | 45 | - All Rows add up to 45; | |
| 3 | 2 | 5 | 9 | 3 | 6 | 8 | 4 | 7 | 1 | 45 | ||
| 4 | 7 | 4 | 2 | 1 | 3 | 5 | 6 | 9 | 8 | 45 | ||
| 5 | 1 | 6 | 5 | 2 | 8 | 9 | 7 | 3 | 4 | 45 | ||
| 6 | 8 | 9 | 3 | 6 | 7 | 4 | 1 | 5 | 2 | 45 | ||
| 7 | 5 | 7 | 6 | 8 | 4 | 3 | 2 | 1 | 9 | 45 | ||
| 8 | 3 | 2 | 4 | 9 | 5 | 1 | 8 | 6 | 7 | 45 | ||
| 9 | 9 | 8 | 1 | 7 | 2 | 6 | 5 | 4 | 3 | 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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