(1) Take

    mylist = [10, 20, 30]

and join it together with '*' characters.

(2) Ask the user to enter multiple hex numbers (digits 0-9,
    and also a-f), separated by whitespace, and sum
    those numbers.

    1234 ab56 ffe4

(3) Ask the user to enter words separated by whitespace.
    Show the number of non-whitespace characters in their
    input.

    this is a test  # 4 + 2 + 1 + 4 = 11