Domino

By systematically checking all possible combinations in a standard double-six set (28 tiles), the tile with two sixes ([6, 6]) is the only one missing from the provided image.

The image contains 27 domino tiles. Upon closer inspection, it is evident that the tile representing [6, 6] is missing, as all other possible combinations from 0 to 6 are present.

By systematically cataloging all 27 visible dominoes in the image and comparing them against the 28 tiles in a standard double-six set, the domino with 2 dots on one end and 4 dots on the other is missing. A complete set contains all combinations from [0,0] through [6,6], totaling 28 unique tiles. The [2,4] domino is not present among the 27 shown.

I systematically catalogued all 27 visible dominoes in the image and compared them against the 28 tiles in a standard double-six set. After checking all combinations from [0,0] through [6,6], the tile [0,3] (blank-three) is the one not present in the image.

After carefully examining the arrangement of 27 dominoes in the image and comparing against the complete list of 28 unique tiles in a double-six set (all pairs from [0,0] to [6,6]), the missing tile is the [2|4] domino, as no representation of two pips opposite four pips is visible.

I identified all 27 shown tiles and compared them to the full double-six set; every pair from 0–6 appears except the double four (4|4), which is not present in the image.

The image contains 27 dominoes from a standard double-six set. By identifying all the double dominoes present, I can see [0,0], [1,1], [2,2], [4,4], [5,5], and [6,6] are all visible in the image. The only double missing from the complete set is [3,3]. Locating the other doubles: [0,0] is in the bottom right (vertical blank-blank), [1,1] is top row rightmost (horizontal), [2,2] is row 4 leftmost (vertical with two dots each), [4,4] is row 2 second position (horizontal), [5,5] is bottom row left (horizontal), and [6,6] is row 4 fourth position (vertical with six dots each). No domino with three dots on both sides appears in the set.