This is Discrete math assignment, please help with Question 5 and 6

Give a recursive definition of the set of even integers. b. the set of positive integers congruent to 2 modulo 3. the set of positive integers not divisible by 5. 5. The reversal of a string is the string consisting of the symbols of the string in reverse order. The reversal of the string w is denoted by wh. Find the reversal of the following bit strings: a. 0101 b. 1 1011 Give a recursive definition of the reversal of a string. [Hint: First define the reversal of the empty string. Then 6. write a string w of length n + 1 as xy, where x is a string of length n, and express the reversal of w in terms of x* and y.]