निम्नलिखित कम्प्यूटेशनल समस्याओं में से कौन सी गणितीय रूप से अनिर्णायक (undecidable) साबित हुई है?

Given the Context-Free Grammar: S → NP VP VP → V NP NP → ART N | N V → ate ART → the N → cat | John Which of the following sentences can be derived using this grammar?

What is the minimum number of states required to construct a Deterministic Finite State Automaton (DFSA) for the set of strings over {a, b} containing an even number of 'a's and an odd number of 'b's?