I assume you mean exactly one 2-of-a-kind . . . and the other 9 cards do not match.If 11 cards are dealt from a 216 card deck (four 54 card decks, 2 jokers each),
what is the probability of there being 2 of a kind (not including jokers)?
Then, what is the probability of the next drawn card making 3 of a kind?
There are: . possible 11-card hands.
There are choices for the value of the pair.
Then there are: . ways to get that pair.
The other nine cards are 'singletons'.
There are: . choices for their values.
There are choices for each value.
Hence, the nine cards can be selected in: . ways.