solve

 sudoku

  to step 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23
  <home

explanations:-
this is step:- 21

 

Note 2
The 5 guess makes a 6 in c8/r3 which in turn makes a 4 in the last cell of column 8.

 


Note 3
Back in step 11 we said that a 6 had to be in column 7 or 8 in row 7, so now it is next to the new 4
Note 1
My first guess is a 5 in c8/r8 as it looks like it will ripple through for a bit.
This makes a 5 in the bottom row of box 7

c1
c2
c3
 
c4
c5
c6
 
c7
c8
c9
 
27 
 
3
 
6
 
 
5
 
4
 
9
 
 
8
 
1
 27
r1
box

1
2
&
3
 
1
258 
258 
 
 
7
box 2 
6
8 3
 
 
4
box 3 
9
235 
r2
 
4
578 
 
9
 
 
2
 
1
 8 3
 
 367
 56
6
357 
r3
 
8
 
4
 
3
 
 
9
 
7
 
5
 
 
1
 
2
 
6
r4
box

4
5
&
6
 
9
box 4 
1
 
2
 
 
6
 
3
 
4
 
 
5
box 6 
7
 
8
r5
 
6
 7 25
7 25 
 
 
8
 24
2
 
1
 
 
9
 
3
 
4
r6
23 
 8 2
4  8
 
 
1
 
5
 
7
 
6 23
6
6 4
4
 
9
r7
box

7
8
&
9
2375 
box 7 
9
4  257
 
3 4
box 8 
8
 
6
 
237 
4 5 
5
 
1
r8
357 
5
 
6
 
1
 
 3 4
 
9
 
2
 
37 
 
8
357 
r9



___________________________________


15th january 2010 © 2014