What is the answer to Life, the Universe, and Everything?
On most definitions, life must be considered a subset of the universe and the universe a subset of (or equivalent to) everything, wherefore your question could be rephrased as "What is the answer to everything?". This, however, is a non-sensical question.
Why? Well, if we look at the analogous question "What is the answer to you?" (substituting one pronoun for another) we find that it can be sensible – in virtue of contextual reference (e.g. a speaker is asking a listener about the answer to some question or other). In "What is the answer to everything?", on the other hand, the pronoun ("everything") is treated as the explanandum (what needs to be explained). If we were to adopt "What is the answer to everything?" as a sensible question we would therefore have to adopt "What is the answer to banana?" as well, since "everything" has no function over and above substituting for nouns.
That said, we all know it is 42.
