I'm confused on the definition of undecidable languages.
Definition: For an undecidable language, there is no Turing Machine which accepts the language and makes a decision for every input string w.
Can you say a language that isn't recognizable as undecidable?
If given a language like
$L = \{\langle M \rangle \mid M$ is a turing machine with more than 50 states i.e. $|Q| > 50 \}$
I have to give an undecidable language T such that $T \subseteq L$.
A language that is a subset I think would be
$L_2 = \{\langle M \rangle \mid M$ is a turing machine with more than 60 states i.e. $|Q| > 60 \}$
because if $\langle M \rangle \in L_2$, then $\langle M \rangle \in L$. Hence, $L_2 \subseteq L$
But I'm confused on the undecidable part. How do I justify if this language is undecidable or if it even is?