Yeah, it's the easiest approach if you allow only 1 answer. With multiple answers allowed we need 64 bits (using trivial encoding and representing each question

Yeah, it's the easiest approach if you allow only 1 answer. With multiple answers allowed we need 64 bits (using trivial encoding and representing each question/answers with 8 bits) or more, if each answer can be assigned "attribute"/priority (say user needs to order answers from the best to the worst).