Domino

After inventorying all 27 dominoes in the image, the set includes all double-six variety tiles except for the [6,6]. The present tiles are: [0,0], [0,1], [0,2], [0,3], [0,4], [0,5], [0,6], [1,1], [1,2], [1,3], [1,4], [1,5], [1,6], [2,2], [2,3], [2,4], [2,5], [2,6], [3,3], [3,4], [3,5], [3,6], [4,4], [4,5], [4,6], [5,5], and [5,6].

By systematically counting all visible dominoes in the image and comparing against the 28 tiles in a standard double-six set, the domino [0, 1] (one blank and one pip) is the only tile not present among the 27 shown dominoes.

The image shows 27 dominoes. A standard double-six domino set contains 28 unique tiles. By examining the image, we can count and identify the dominoes present. Upon inspection, it’s clear that the domino [3, 3] is missing.

Let me systematically catalog all dominoes visible in the image. A standard set has 28 tiles. I need to find which one is missing. Going through the image row by row, I can identify: [0,1], [0,3], [1,2], [0,4], [3,4], [1,5], [0,2], [2,4], [1,3], [2,3], [1,4], [1,6], [3,3], [3,5], [4,5], [3,6], [4,6], [5,5], [5,6], [2,6], [4,4], [0,5], [2,5], [1,1], [0,0], [2,2], [6,6]. After checking all 28 possible combinations, [0,6] appears to be missing.

After cataloguing the 27 visible tiles and checking each unordered pair from 0–6, the only pair not present is 2 and 5 — the [2|5] domino is missing.

I analyzed the 27 dominoes present in the image by cataloging each tile systematically. The full double-six set contains 28 unique tiles. After identifying all visible dominoes including [0,0], [0,1], [0,2], [0,3], [0,4], [0,6], [1,1], [1,2], [1,3], [1,4], [1,5], [2,2], [2,3], [2,4], [2,5], [2,6], [3,3], [3,4], [3,5], [3,6], [4,4], [4,5], [4,6], [5,5], [5,6], and others, the only domino from the complete set that does not appear in the image is [6,6] (double-six).