solve

 sudoku

  step 1 2 3 4 5 6 7 8 9 10
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A very easy puzzle to get the idea of how sudoku is solved
Roger Walker
explanations:-
this is step 9


c3 has a 2 in its last cell in box 7 which makes a 7 in the last cell of box 7.

Now c1 has only one cell left for a 2 in c1r1, and a 7 completes Box 1 and c2.

c4 also has only one cell free at c4r2 for the missing 2.

Box 8 is short of a 3 and a 7 but the existing 7 in c5 decides the placing. Just a 1 to finish off c5 at c5r3.

The last two numbers in Box 2 are 3 and 8 and are the opposite of 3 and 8 in Box 1.

r2 is short of a 1 and r3 needs a 2 to finish.

r1 needs 7 and 8 but the 7 in c9r4 decides the position.

c1
c2
c3
 
c4
c5
c6
 
c7
c8
c9
 
 
2

 4

1
   
5
 
9

6
   
7

3
 
8
r1
box

1
2
&
3
 
3
-box 1-
7
 
6
   
2
-box 2-
4
 
8
 
9
- box 3 
1

5
r2

8
 
 
9
 
7
 
1
 
3
   
2

4
 
6
r3

9

8

3
   
4

2
 
1
 
6 
 
5

7
r4
box

4
5
&
6
 
6
- box 4 
1

4
 
8
- box 5 -
7

5
   
- box 6 
9

 
r5

5
 
2

7
 
3

6

9
 
1
 
8

4
r6
 
7

3
 
8
 
1

5
 
2
  4
6

9
r7
box

7
8
&
9

4
- box 7 
9

5
 
6
- box 8
3
 
7
 
 
box 9 
 

 
r8
 
1

6

2
 
9

8

4
 
5

 

 
r9




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15th january 2010 © 2014