NUmber of ways to answer a question?

[Neurocscience]

A multiple choice question has 5 answers, anything from one to all the choices can be marked(more than one choice can be marked at a time). How many ways are there to answer the question? While waiting for on my chem question, I want to see how hard it would be to guess my way to the answer I think I did this in precalc last year..something about series..I can't really remember.

 

[Tide]

HINT: You can either choose an answer or not choose an answer.