Hello and welcome to this course on the Naked Triplets technique!
This technique is a variation of the naked pair technique. If there are three cells in a house that have the same 3 candidates, you can eliminate those 3 candidates from all other cells in that house.
The Naked Triplets Technique
Let's see how to put this technique into practice.
Cell number 2 has been annotated entirely and we can see that cells R1-C5, R2-C4 and R2-C6 share the same candidates, 5, 7 and/or 9.
If we look at cell R1-C4, we can see that this is the only cell that has candidate 2. So we can safely delete the other candidates in this cell, because we are sure that 5 and 9 will be in the other cells, and so only 2 is left.
Another more complex example
The previous example was rather obvious and easy to apply. In this new example, we will see that it is possible to have triplets by combining several cells.
In cell number 7, all the cells are annotated. We can see that the three marked cells each have two candidates, but if we put the candidates together, it forms a triplet (candidates 1, 3 and 7).
In this case, no other cell can be 1, 3 or 7, so we can eliminate them from all other cells.