Hidden Triple
mediumWhen three cells in a Region contain the same three digits (or a subset of them), and those digits don’t appear in any other cell in the Region, this is called a Hidden Triple. The three cells must contain only those digits, and any other candidates in these cells can be eliminated.
When three cells in a region contain the same three digits (or a subset of those three), and these digits appear in no other cell in the region, they form a Hidden Triple.
The three cells must contain these three digits, and all other candidates in these cells can be eliminated.
Example 1
In the shaded Region (Column 9), the digits 2, 3, and 6 can only appear in three cells: E9, F9, and G9. The remaining candidates in these three cells can be eliminated (highlighted in red).
Example 2
In the shaded Region (Box 6), the digits 1, 5, and 6 can only be placed in three cells: E7, F8, and F9. Therefore, the remaining candidates in these three cells can be eliminated.
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