Pairs and Triples

Pairs and triples use sets of candidates that are confined to a small number of cells in one house.

Naked Pair

If two cells in one house contain only the same two candidates, remove those two digits from the rest of the house.

In the example above 5 and 6 are the only candidates in R1C1 and R1C2. They form a naked pair in row 1 and box 1. Remove the red 5s and 6s from the other cells of box 1.

Hidden Pair

If two digits can only appear in the same two cells of a house, remove all other candidates from those two cells.

In the example above 1 and 2 can only appear in R1C1 and R1C2. Remove the other candidates in those cells (red).

Naked Triple

If three cells in one house contain only the same three candidates, remove those digits from the rest of the house.

In the example above 2, 4 and 9 are the only candidates in R5C7, R5C8 and R5C9. They form a naked triple in row 5 and box 6. Remove the red candidates from the other cells of the house.

Hidden Triple

If three digits can only appear in the same three cells of a house, remove all other candidates from those cells.

In the example above 1, 5 and 6 form a hidden triple in box 8. Remove the other candidates in R7C6, R8C4 and R8C6 (red).