The New Sudoku Players' Forum

[SuDokuKid]

I have a box of candidates.

137, 23, 13, 137

Is there a triplet that I just can't figure out? If there is, why?

Can someone post several possible triplet lines like this as a test or something to find triplets? I just can't get the hang of it. Its driving me crazy.

Thanks!

[Heuresement]

137, 23, 13, 137

The triplet is 1,3 and 7.

However, what is easier to see is that the 2 can only go in the second cell, leaving behind 137, 13, and 137 in the other three cells, hence the triplet.

[SuDokuKid]

Thanks!

What if it was: 137,13,23,1237

Is the 137 still a triplet? And I would end up with:

137,13,2,137 once again?

Would you mind posting just a few lines of triplets and explaining them? I don't want to go over board, but just samples other than the repeated ones I'm finding online which seem aren't 'complete' in their explanations.

I'd appreciate it.

[Nick67]

This nice post by tso on triples is close to what you request.

Let me add this bit: the following are all possible combinations of
1, 2, and 3 that form a triple:

123 123 123

123 123 12

123 123 13

123 123 23

123 12 23

123 12 13

123 13 23

12 23 13

(assuming order doesn't matter, and leaving out combinations that contain a naked single
or naked pair, like 123 12 12 )

[SuDokuKid]

So based on tso explanation, my second example is not a triple?

137,13,23,1237

Becuse the two of the cells contain a 2?

[NorwegianViking]

Exactly

[cho]

So based on tso explanation, my second example is not a triple?

137,13,23,1237

Becuse the two of the cells contain a 2?

It might help you to realize that any hidden set (double, triple, quad) has to be accompanied with a naked set. It is obvious that you should have an equal number of candidates and un-solved cells in a given group. So your naked set will be be whatever remains after exposing the hidden set. By the same token if you spot the naked set first, the hidden set will be exposed when you reduce candidates. So in order to have a triple in four cells there must be a single.

To illustrate, the following row contains a hidden triple (135) and a naked triple (689). After recognizing and acting on either one you will be left with two naked triples.

Code: Select all

 | 2 1369 68 | 7  89 359 | 1568 4 69 |

cho

[Cec]

".......

Can someone post several possible triplet lines like this as a test or something to find triplets? I just can't get the hang of it. Its driving me crazy.

Thanks!

Hi SuDokuKid,

I think it's worth quoting part of Angusj's simple but very clear definition for Naked and Hidden Triples. I've highlighted what I believe are the key words:

(a) Naked Triple - occurs when three cells in a group contain no candidates other than the same three candidates. The cells which make up a Naked Triple don't have to contain every candidate of the triple. If these candidates are found in other cells in the group they can be excluded...."

(b) Hidden Triple - occurs when three candidates are restricted to three cells in a given group which then enables all other candidates in those three cells to be excluded

Cec

[kchyde@cox.net]

I have the following line
238,28,37,3789,6,4,5,1,389

then down the right side I have
389,348,348,7,2,5,6,1,349

How does the triplet help me solve these two lines?
I see on the right side four cells need to contain 3,8,9,4 but how can I determine which one goes where?

Kevin

[Crazy Girl]

Kevin

could you post the whole puzzle, as far as you have got, with candidates for remaining blank cells.

In the row, there does not appear to be any triplet or quad but can't be certain as i've not seen all of puzzle.

In the column, you have a quad, where the numbers go will be decided by cells in another column.

[9X9]

KCH

I imagine your two "lines" are 1) a row and 2) a column.

The row does not appear to contain a triple (which I think is what you mean by a "triplet"). To make this clearer, firstly exclude the 3s and 8s from your thinking, because there are four of them in each case and therefore they cannot be part of any triple. Then you will see that one or more of the remaining three candidates, the 2s 7s and 9s, appear(s) in more than three cells in total, so that they cannot form a triple.

The column does not appear to contain a triple. Firstly exclude the 3s from your thinking, because there are four of them and therefore they cannot be part of any triple. Then you will see that one or more of the remaining three candidates, the 4s 8s and 9s, appear(s) in more than three cells in total, so that they cannot form a triple.

The column does appear to contain a (so called "naked") quad, four cells containing only combinations of 3, 4, 8 and 9 but there are no other cells in the column containing any of these candidates and therefore there are no related eliminations possible in the column. There is insufficient information in the column alone to assist in the ultimate placement of any of the individual quad candidates.

Do you know and understand www.angusj.com ?

[Cec]

".....How does the triplet help me solve these two lines?..."
Kevin

Hi Kevin,

To complement Crazy Girl and 9X9's above responses to you that no triple appears to exist in either of the two groups (row/column) of numbers you submitted I suggest you read my above reply to SudokuKid who likewise sought assistance in understanding this same problem. To help make it clearer I highlighted the key words for identifying the existence of a triple (or triplet if you prefer that terminology).

Identification of a naked triple in a group (row, column or box) requires that three cells and only three cells contain no candidates other than the same three candidates. Note that each of the three cells making up the triple don't have to contain all of the three candidates. In the case of a hidden triple, once again, the three candidates making up this triple are contained only in three cells.

The groups of numbers you submitted do not meet the above criteria either for a naked triple or hidden triple. The angusj site http://www.angusj.com/sudoku/hints.php clearly explains practicable examples for identifying both naked and hidden triples.

Cec

[kchyde@cox.net]

Thank you all for the help. I think I got it now! I've since solved the puzzle and I'll give my new found understanding a try.

Thanks again!