Domino

Reasoning

The excluded domino is number 0 and 0

Reasoning

Counting the visible halves for each pip value shows every number 0–6 appears the expected eight times except the 5s, which appear only six times; therefore the missing tile must be the double five (5,5).

Reasoning

By counting the occurrences of each number across all halves of the 27 dominoes, numbers 0,1,3,4,6 appear 8 times each, while 2 and 5 appear 7 times each, indicating the missing domino is [2-5].

Reasoning

A full standard double-six set of dominoes has 28 unique tiles. By identifying the 21 unique tiles visible in the image, we determined that all tiles containing the number ’1’ (i.e., [0, 1], [1, 2], [1, 3], [1, 4], [1, 5], and [1, 6]) are present, with the exception of the double [1, 1]. Although the image contains multiple discrepancies (only 26 tiles are shown, resulting in 7 overall unique tiles missing if no visual identification errors occurred), [1, 1] is the only tile missing that completes the entire sub-set of tiles containing the number 1.

Reasoning

The full set contains 28 dominoes with numbers 0-6. Each number should appear 8 times across all tiles (28 tiles × 2 sides = 56 total dots; 56 ÷ 7 numbers = 8 per number). Counting the occurrences of 6 in the image shows it appears only 6 times (from dominoes (0,6), (1,6), (2,6), (3,6), (4,6), and (5,6)), which is 2 less than the required 8. This discrepancy is explained by the missing double-six domino (6,6), which contributes 2 to the count of 6. All other numbers appear the correct number of times, confirming (6,6) is the missing tile.

Reasoning

By systematically checking all 28 possible dominoes in a standard double-six set, I identified 27 dominoes in the image. The missing domino is [2, 4], which would represent a tile with 2 dots on one end and 4 dots on the other end.