Naked Pair, Triplet, Quad...
If a container has a pair of cells that have just two possible digits, you can eliminate those digits from all the other cells in the container, a strategy called a “naked pair” or more generally a “naked subset”. It works with any number of cells - three cells that contain the same three digits are a “naked triplet”, four cells that contain the same four digits form a “naked quad”, and so on.
The following row contains a naked pair (5,3) in the highlighted squares. These squares monopolize those numbers. 5 and 3 can be eliminated elsewhere in the row by erasing the numbers I’ve crossed out.
The next puzzle contains several naked pairs and triplets, of which I've highlighted a triplet and a pair.
Notice that in the triplet in row 1, it is not necessary for each of the three cells to contain all three digits. Between them, the three cells will contain just the digits 2, 4, and 8, so we can eliminate those digits from all the other cells in the top row.
Can you find any other naked pairs and triplets in this puzzle?