Hidden Triple
Prerequisites: Hidden Pair
Overview
Three candidates confined to exactly three cells within a house. All other candidates can be removed from those cells.
How It Works
If digits X, Y, and Z appear only in cells A, B, and C within a house, those digits must occupy those cells. Any other candidates in A, B, and C can be eliminated.
When To Use It
When three digits in a house are restricted to the same three cells but those cells also contain extra candidates.
How To Detect It
For each house, examine triples of digits. If the union of cells containing those digits has exactly 3 cells, it is a hidden triple.
Visual Example
Step 1 of 9
Three Digits Confined to Three Cells
A Hidden Triple occurs when three digits are collectively confined to the same three cells within a house. Each digit may appear in two or all three of those cells, but nowhere else in the house.
Practice
A Hidden Triple is hiding here. Find it, strip the extra candidates, and fill the single it unlocks.