The difference between the number of states in minimal DFA and minimal NFA, which accepts all strings end with 3rd bit as b is _____. [ Assume $\sum$ = {a,b} ]

In the NFA there are minimum of 4 states and when the NFA converted to DFA the number of states are 8 and that is minimum also. Now the difference b/w them is

How may Moore/Mealy m/c are possible with two states X & Y for the input alphabet {a, b} and output alphabet {0, 1} , where x is always the initial state?

Consider the following DFA: The number of distinct sets present in all partitions while converting given DFA into minimal DFA using Myhill-Nerode theorem is ________.