For example, the answer to a) is probably S->10, S->01, S->101. The rest are more complicated.

Find a phrase-structure grammar for each of these languages. a) the set consisting of the bit strings 10, 01, and 101 b) the set of bit strings that start with 00 and end with one or more Is c) the set of bit strings consisting of an even number of Is followed by a final 0 d) the set of bit strings that have neither two consecutive 0s nor two consecutive 1 s