Non-Adjacent Selection from 1 to 10
You pick 3 numbers uniformly at random from the set $\{1, 2, \ldots, 10\}$ (all $\binom{10}{3}$ subsets equally likely). The catch: the selection is only valid if no two chosen numbers are adjacent -- meaning no two differ by exactly 1.
What is the probability that a random 3-element subset satisfies this non-adjacency condition?
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