Let $$L$$ denote the language generated by the grammar $$S \to 0S\left. 0 \right|00.$$ Which one of the following is true?

Consider the regular expression $$(0+1)(0+1).......n$$ times. The minimum state finite automation that recognizes the language represented by this regular expression contains:

How many substrings of different lengths (non-zero) can be formed from a character string of length $$n$$ ?

If the regular set $$A$$ is represented by $$A = {\left( {01 + 1} \right)^ * }$$ and the regular set $$'B'$$ is represented by $$B = \left( {{{\left( {01} \right)}^ * }{1^ * }} \right),$$ which of the following is true?