Could you provide python code to;

a) Print out contents of a 'list' if integers in reverse without using "list.reverse()"

b) Take a list and an integer 'n' as input and interates through the list printing out every n'th element from last to first

c) Print out Fail or Pass depending on whether a mark is below 40 or not. Create a test variable called mark and give it values that will test your code. Check whether a mark is valid. Valid marks range from 0 to 100 inclusive.