2) Write regular expressions over the vocabulary { 0, 1 } for each of the following:

a) All strings which, when interpreted as binary numbers, represent all non-negative numbers divisible by 4.

b) All strings consisting of two-or-more 1's followed by a non-empty sequence of 0's.

c) All strings containing the substring 101, and ending in a 1.

d) All strings consisting of n 0's, followed by 2n 1's (where n is an arbitrary non-negative integer.)

Your answers should be written using the regex syntax presented in class.