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Easy Puzzle #24 - 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       2 6   Easy Puzzle #24 - October 24, 2005
2 2   4 9 8         One possible Solution Method follows below…
3 5 1   6       3 8
4 7   6   1     9  
5   2   3   4   1  
6   9     6   3   2
7 6 8       1     3
8         5 9 8   6
9   5 2       7    
A B C D E F G H I
1     8       2 6   Step 1: #6 is in Columns A & C: #6 MUST go in Cell B2
2 2 6 4 9 8              (cf #6 in Row 1 @ I1 excludes use of Cell B1)
3 5 1   6       3 8
4 7   6   1     9   Step 2: #8 is in Columns G & I: #8 MUST go in Cell H6
5   2   3   4   1  
6   9     6   3 8 2
7 6 8       1     3
8         5 9 8   6
9   5 2       7    
A B C D E F G H I
1     8       2 6   Step 3: #8 is in Column B & C: #8 MUST go in Cell A5
2 2 6 4 9 8              (cf #8 in row 6 @ H6 excludes use of Cell A6)
3 5 1   6       3 8
4 7   6   1     9   Step 4: #9 is in Columns D & F: #9 MUST go in Cell E5
5 8 2   3 9 4   1  
6   9     6   3 8 2
7 6 8       1     3
8         5 9 8   6
9   5 2       7    
A B C D E F G H I
1     8       2 6   Step 5: #6 is in Columns H & I: #6 MUST go in Cell G5
2 2 6 4 9 8              (cf #6 in row 4 @ C4 excludes use of Cell G4)
3 5 1   6       3 8
4 7   6   1     9  
5 8 2   3 9 4 6 1  
6   9     6   3 8 2
7 6 8       1     3
8         5 9 8   6
9   5 2       7    
A B C D E F G H I
1     8       2 6   Step 6: Block II needs #1: #1 MUST go in Cell I9
2 2 6 4 9 8   1          (NB: #1 in Column H @ H5 excludes use of H7,H8,H9
3 5 1   6       3 8        & #1 in Row 7 @ F7 excludes use of G7)
4 7   6   1     9  
5 8 2   3 9 4 6 1   Step 7: Block CC needs #1: #1 MUST go in Cell G2
6   9     6   3 8 2      (cf #1 in Columns H & I exclude Cells H2, I1 & I2,
7 6 8       1     3        & #1 in Row 3 @ B3 excludes Cell G3)
8         5 9 8   6
9   5 2       7   1
A B C D E F G H I
1     8 1     2 6   Step 8: #1 is in Rows 2 & 3: #1 MUST go in Cell D1
2 2 6 4 9 8   1          (#1 in Column E @ E4 excludes use of Cell E1, &
3 5 1   6       3 8        #1 in Column F @ F7 excludes use of Cell F1)
4 7 3 6   1     9  
5 8 2   3 9 4 6 1   Step 9: #3 is in Rows 5 & 6: #3 MUST go in Cell B4
6   9     6   3 8 2
7 6 8       1     3
8         5 9 8   6
9   5 2       7   1
A B C D E F G H I
1     8 1     2 6   Step 10:  Block DD needs #4: #4 MUST go in Cell A6
2 2 6 4 9 8   1          (NB: #4 in Column C @ C2 excludes use of C5 & C6
3 5 1   6       3 8
4 7 3 6   1     9  
5 8 2   3 9 4 6 1  
6 4 9     6   3 8 2
7 6 8       1     3
8         5 9 8   6
9   5 2       7   1
A B C D E F G H I
1     8 1     2 6   Step 11: Complete Block DD: need #s 1 & 5…
2 2 6 4 9 8   1          #1 can't go in Cell C5 (cf #1 in Row 5 @ H5), so
3 5 1   6       3 8      #1 MUST go in Cell C6, & therefore #5 MUST go in Cell C5
4 7 3 6   1     9  
5 8 2 5 3 9 4 6 1   Step 12: #1 is in Rows 7 & 9: #1 MUST go in Cell A8
6 4 9 1   6   3 8 2      (cf #1 in Column B @ B3 excludes use of Cell B8, &
7 6 8       1     3        #1 in Column C @ C6 excludes use of Cell C8)
8 1       5 9 8   6
9   5 2       7   1
A B C D E F G H I
1 3   8 1     2 6   Step 13: Complete Row 5: #7 MUST go in Cell I5
2 2 6 4 9 8   1    
3 5 1   6       3 8 Step 14: Block AA needs #3: #3 MUST go in Cell A1
4 7 3 6   1     9        (#3 in Column B excludes Cell B1, & #3 in Row 3 @ H3
5 8 2 5 3 9 4 6 1 7        excludes use of Cell C3)
6 4 9 1   6   3 8 2
7 6 8       1     3 Step 15: Now #3 is in Columns A & B: #3 MUST go in Cell C8
8 1   3   5 9 8   6      (#3 in Row 7 @ I7 excludes use of Cell C7)
9   5 2       7   1
A B C D E F G H I
1 3 7 8 1     2 6   Step 16: Complete Block AA: need #s 7 & 9…
2 2 6 4 9 8   1          #9 can't go in Cell B1 (cf #9 in Column B @ B6), so
3 5 1 9 6       3 8      #9 MUST go in Cell C3, & therefore #7 MUST go in Cell B1
4 7 3 6   1     9  
5 8 2 5 3 9 4 6 1 7
6 4 9 1   6   3 8 2
7 6 8       1     3