| Very Easy Puzzle #31 - 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 | 7 | 2 | 1 | 3 | 6 | 8 | Very Easy Puzzle #31 - October 31, 2005 | ||||
| 2 | 4 | 9 | 8 | 6 | 3 | 1 | Original puzzle as published © joe-ks.com | ||||
| 3 | 8 | 3 | 2 | 5 | 4 | ||||||
| 4 | 7 | 1 | 3 | 5 | |||||||
| 5 | 1 | 8 | 5 | 7 | 6 | ||||||
| 6 | 3 | 6 | 7 | 4 | |||||||
| 7 | 9 | 2 | 6 | 4 | 7 | ||||||
| 8 | 5 | 4 | 8 | 1 | 3 | ||||||
| 9 | 3 | 4 | 1 | 9 | 6 | 5 | |||||
| A | B | C | D | E | F | G | H | I | |||
| 1 | 7 | 2 | 1 | 3 | 6 | 8 | Step 1: #6 is in Rows 1 & 2: #6 MUST go in Cell B3... | ||||
| 2 | 4 | 9 | 8 | 6 | 3 | 1 | |||||
| 3 | 8 | 6 | 3 | 2 | 5 | 4 | Step 2: #3 is in Rows 4 & 6: #3 MUST go in Cell H5... | ||||
| 4 | 7 | 1 | 3 | 5 | |||||||
| 5 | 1 | 8 | 5 | 7 | 3 | 6 | Step 3: #9 is in Rows 7 & 9: #9 MUST go in Cell E8... | ||||
| 6 | 3 | 6 | 7 | 4 | |||||||
| 7 | 9 | 2 | 6 | 4 | 7 | ||||||
| 8 | 5 | 4 | 9 | 8 | 1 | 3 | |||||
| 9 | 3 | 4 | 1 | 9 | 6 | 5 | |||||
| A | B | C | D | E | F | G | H | I | |||
| 1 | 7 | 2 | 1 | 3 | 6 | 8 | Step 4: Complete Block AA: #5 MUST go in Cell C2... | ||||
| 2 | 4 | 9 | 5 | 8 | 6 | 3 | 1 | ||||
| 3 | 8 | 6 | 3 | 2 | 5 | 4 | Step 5: #5 is now in Columns B & C: #5 MUST go in Cell A6 | ||||
| 4 | 7 | 1 | 3 | 5 | (#5 in Row 4 @ H4 excludes use of Cell A4) | ||||||
| 5 | 1 | 8 | 5 | 7 | 3 | 6 | |||||
| 6 | 5 | 3 | 6 | 7 | 4 | Step 6: Complete Block II: need #s 2 & 8… | |||||
| 7 | 9 | 2 | 6 | 4 | 8 | 7 | #8 can't go in Cell G8 (cf #8 in Row 8 @ F8), so | ||||
| 8 | 5 | 4 | 9 | 8 | 2 | 1 | 3 | #8 MUST go in Cell H7, & therefore #2 MUST go in Cell G8 | |||
| 9 | 3 | 4 | 1 | 9 | 6 | 5 | |||||
| A | B | C | D | E | F | G | H | I | |||
| 1 | 7 | 2 | 1 | 3 | 6 | 8 | Step 7: Block HH needs #7: #7 MUST go in Cell D9 | ||||
| 2 | 4 | 9 | 5 | 8 | 6 | 3 | 1 | (#7 in Column F @ F6 excludes use of Cells F7 & F9, & | |||
| 3 | 8 | 6 | 3 | 2 | 5 | 4 | #7 in Row 7 further excludes use of Cell D7) | ||||
| 4 | 7 | 1 | 3 | 5 | |||||||
| 5 | 1 | 8 | 5 | 7 | 3 | 6 | Step 8: #7 is now in Rows 7 & 9: #7 MUST go in Cell C8 | ||||
| 6 | 5 | 3 | 6 | 7 | 4 | (#7 in Column A excludes use of Cell A8) | |||||
| 7 | 9 | 2 | 6 | 4 | 8 | 7 | |||||
| 8 | 5 | 7 | 4 | 9 | 8 | 2 | 1 | 3 | |||
| 9 | 3 | 4 | 7 | 1 | 9 | 6 | 5 | ||||
| A | B | C | D | E | F | G | H | I | |||
| 1 | 7 | 2 | 1 | 3 | 6 | 8 | Step 9: Complete Row 8: #6 MUST go in Cell A8... | ||||
| 2 | 4 | 9 | 5 | 8 | 6 | 3 | 1 | ||||
| 3 | 8 | 6 | 3 | 2 | 5 | 4 | Step 10: Complete Column C: need #s 6 & 9… | ||||
| 4 | 7 | 6 | 1 | 3 | 8 | 5 | #6 can't go in Cell C6 (cf #6 in Row 6 @ D6), so | ||||
| 5 | 1 | 8 | 5 | 7 | 3 | 6 | #6 MUST go in Cell C4, & therefore #9 MUST go in Cell C6 | ||||
| 6 | 5 | 3 | 9 | 6 | 7 | 1 | 4 | ||||
| 7 | 9 | 2 | 6 | 4 | 8 | 7 | Step 11: Complete Column G: need #s 1 & 8… | ||||
| 8 | 6 | 5 | 7 | 4 | 9 | 8 | 2 | 1 | 3 | #1 can't go in Cell G4 (cf #1 in Row 4 @ D4), so | |
| 9 | 3 | 4 | 7 | 1 | 9 | 6 | 5 | #1 MUST go in Cell G6, & therefore #8 MUST go in Cell G4 | |||
| A | B | C | D | E | F | G | H | I | |||
| 1 | 7 | 2 | 1 | 3 | 6 | 8 | Step 12: Complete Block GG: need #s 1 & 8… | ||||
| 2 | 4 | 9 | 5 | 8 | 6 | 3 | 1 | #1 can't go in Cell B9 (cf #1 in Row 9 @ E9), so | |||
| 3 | 8 | 6 | 3 | 2 | 5 | 4 | #1 MUST go in Cell B7, & therefore #8 MUST go in Cell B9 | ||||
| 4 | 2 | 7 | 6 | 1 | 3 | 8 | 5 | 9 | |||
| 5 | 1 | 8 | 5 | 7 | 3 | 6 | Step 13: Complete Column A: #2 MUST go in Cell A4... | ||||
| 6 | 5 | 3 | 9 | 6 | 7 | 1 | 4 | 2 | |||
| 7 | 9 | 1 | 2 | 6 | 4 | 8 | 7 | Step 14: Complete Column I: need #s 2 & 9… | |||
| 8 | 6 | 5 | 7 | 4 | 9 | 8 | 2 | 1 | 3 | #9 can't go in Cell I6 (cf #9 in Row 6 @ I6), so | |
| 9 | 3 | 8 | 4 | 7 | 1 | 9 | 6 | 5 | #9 MUST go in Cell I4, & therefore #2 MUST go in Cell I6 | ||
| A | B | C | D | E | F | G | H | I | |||
| 1 | 7 | 2 | 1 | 3 | 4 | 6 | 8 | Step 15: Complete Block DD: #4 MUST go in Cell B5… | |||
| 2 | 4 | 9 | 5 | 8 | 6 | 3 | 1 | ||||
| 3 | 8 | 6 | 3 | 2 | 5 | 4 | Step 16: Complete Row 4: #4 MUST go in Cell E4... | ||||
| 4 | 2 | 7 | 6 | 1 | 4 | 3 | 8 | 5 | 9 | ||
| 5 | 1 | 4 | 8 | 5 | 7 | 3 | 6 | Step 17: #4 is now in Columns D & E: #4 MUST go in Cell F1 | |||
| 6 | 5 | 3 | 9 | 6 | 7 | 1 | 4 | 2 | (#4 in Row 3 @ I3 excludes use of Cell F3) | ||
| 7 | 9 | 1 | 2 | 6 | 4 | 8 | 7 | ||||
| 8 | 6 | 5 | 7 | 4 | 9 | 8 | 2 | 1 | 3 | Step 18: Complete Row 9: #2 MUST go in Cell F9… | |
| 9 | 3 | 8 | 4 | 7 | 1 | 2 | 9 | 6 | 5 | ||
| A | B | C | D | E | F | G | H | I | |||
| 1 | 7 | 2 | 1 | 5 | 3 | 4 | 6 | 8 | Step 19: Complete Block HH: need #s 3 & 5… | ||
| 2 | 4 | 9 | 5 | 8 | 6 | 3 | 1 | #3 can't go in Cell F7 (cf #3 in Column F @ F4), so | |||
| 3 | 8 | 6 | 3 | 2 | 5 | 4 | #3 MUST go in Cell D7, & therefore #5 MUST go in Cell F7 | ||||
| 4 | 2 | 7 | 6 | 1 | 4 | 3 | 8 | 5 | 9 | ||
| 5 | 1 | 4 | 8 | 5 | 7 | 3 | 6 | Step 20: #5 is now in Columns E & F: #5 MUST go in Cell D1 | |||
| 6 | 5 | 3 | 9 | 6 | 8 | 7 | 1 | 4 | 2 | (#5 in Row 3 @ G3 excludes use of Cell D3) | |
| 7 | 9 | 1 | 2 | 3 | 6 | 5 | 4 | 8 | 7 | ||
| 8 | 6 | 5 | 7 | 4 | 9 | 8 | 2 | 1 | 3 | Step 21: Complete Row 6: #8 MUST go in Cell E6... | |
| 9 | 3 | 8 | 4 | 7 | 1 | 2 | 9 | 6 | 5 | ||
| A | B | C | D | E | F | G | H | I | |||
| 1 | 7 | 2 | 1 | 5 | 3 | 4 | 6 | 8 | Step 22: Complete Column EE: need #s 2 & 9… | ||
| 2 | 4 | 9 | 5 | 8 | 6 | 3 | 1 | #2 can't go in Cell F5 (cf #2 in Column F @ F9), so | |||
| 3 | 8 | 6 | 3 | 9 | 2 | 5 | 4 | #2 MUST go in Cell D5, & therefore #9 MUST go in Cell F5 | |||
| 4 | 2 | 7 | 6 | 1 | 4 | 3 | 8 | 5 | 9 | ||
| 5 | 1 | 4 | 8 | 2 | 5 | 9 | 7 | 3 | 6 | Step 23: #9 is now in Columns E & F: #9 MUST go in Cell D3 | |
| 6 | 5 | 3 | 9 | 6 | 8 | 7 | 1 | 4 | 2 | ||
| 7 | 9 | 1 | 2 | 3 | 6 | 5 | 4 | 8 | 7 | ||
| 8 | 6 | 5 | 7 | 4 | 9 | 8 | 2 | 1 | 3 | ||
| 9 | 3 | 8 | 4 | 7 | 1 | 2 | 9 | 6 | 5 | ||
| A | B | C | D | E | F | G | H | I | |||
| 1 | 7 | 2 | 1 | 5 | 3 | 4 | 6 | 8 | Step 24: Complete Block BB: need #s 1 & 7… | ||
| 2 | 4 | 9 | 5 | 8 | 7 | 6 | 3 | 1 | #1 can't go in Cell E2 (cf #1 in Row 2 @ I2), so | ||
| 3 | 8 | 6 | 3 | 9 | 2 | 1 | 5 | 7 | 4 | #1 MUST go in Cell F3, & therefore #7 MUST go in Cell E2 | |
| 4 | 2 | 7 | 6 | 1 | 4 | 3 | 8 | 5 | 9 | ||
| 5 | 1 | 4 | 8 | 2 | 5 | 9 | 7 | 3 | 6 | Step 25: #7 is now in Rows 1 & 2: #7 MUST go in Cell H3… | |
| 6 | 5 | 3 | 9 | 6 | 8 | 7 | 1 | 4 | 2 | ||
| 7 | 9 | 1 | 2 | 3 | 6 | 5 | 4 | 8 | 7 | ||
| 8 | 6 | 5 | 7 | 4 | 9 | 8 | 2 | 1 | 3 | ||
| 9 | 3 | 8 | 4 | 7 | 1 | 2 | 9 | 6 | 5 | ||
| A | B | C | D | E | F | G | H | I | |||
| 1 | 7 | 2 | 1 | 5 | 3 | 4 | 6 | 9 | 8 | Step 26: Complete Block CC (& Puzzle): need #s 2 & 9… | |
| 2 | 4 | 9 | 5 | 8 | 7 | 6 | 3 | 2 | 1 | #2 can’t go in Cell H1 (cf #2 in Row 1 @ B1), so | |
| 3 | 8 | 6 | 3 | 9 | 2 | 1 | 5 | 7 | 4 | #2 MUST go in Cell H2, & therefore #9 MUST go in Cell H1 | |