## Totally stumped!

Advanced methods and approaches for solving Sudoku puzzles

### Totally stumped!

Hi, I'm still fairly new to the puzzles and trying to learn all the techniques. I've worked this puzzle 4 times and end up in the same place. Please tell me what I am not seeing here in order to continue. Thanks.

1(56)(47)9(24)(356)(237)(2378)(78)
9 3 2 1 8 7 4 6 5
(56)8(47)(356)(24)(356)(237)19
(57)(21)3(47)6(59)8(2579)(147)
4(56)82(59)1(567)(579)3
(567)(21)9(47)38(12567)(257)(1467)
27(156)(3568)(159)(3569)(1356)4(168)
34(156)(568)729(58)(168)
89(156)(356)(15)4(13567)(357)2
gklittle

Posts: 13
Joined: 13 October 2005

in row 5 the 7 must be in the third box so you can eliminate the other 7's from that box and you get that r1c9 is 7
bennys

Posts: 156
Joined: 28 September 2005

### Totally stumped no more!

Thank you so much, Bennys. I can't believe I missed that each time. Puzzle solved!!
gklittle

Posts: 13
Joined: 13 October 2005

### Totally stumped!

bennys wrote:in row 5 the 7 must be in the third box so you can eliminate the other 7's from that box and you get that r1c9 is 7

Hi bennys

I can see how candidate 7's are locked in row 5 (Box 6) -you refer to this as Box 3 and which enables the remaining 7's in this box to be eliminated.

There are some naked pairs (59) in box 5 which gives another naked pair (47) in this same box (c4) and another naked pair (56) in c2 (boxes 1 and 4) but interested to know how you determine that a 7 goes in cell r1c9. (box3).

Bonsai Cec
Cec

Posts: 1039
Joined: 16 June 2005

After you eliminate the 7's from the other cells in boxs 3 the only 7 candidat in c9 is in r1
bennys

Posts: 156
Joined: 28 September 2005

The only 7's in R5 are in Box 6. This removes the candidate 7's from R4 and R6 in Box 6. This makes the 7 in Box 3 unique in C9.

stuartn
stuartn

Posts: 211
Joined: 18 June 2005

### Totally stumped!

Thanks to all above. Still kicking myself for omitting to include clue 2 in cell r9c9 which gave me another candidate 7 in this cell and hence not seeing what is now obvious. Lesson for Cec? Measure twice - cut once.

Bonsai Cec
Cec

Posts: 1039
Joined: 16 June 2005