Sgt_Kickaxe - 4:11 am on Sep 19, 2012 (gmt 0)
There was a leaked Google rater document from June 2012 (linked to from the Shoemoney site I believe). On page 94, under the *poor* rating, is an example that states a page is of poor quality if there is no answer to a question yet but it takes time to figure that out.
That suggests that pages with answers and pages that make it clear quickly that there is no answer yet rank more highly than those in which you waste a lot of time reading/scrolling only to find out there isn't an answer(yet).
Your question then becomes "Will a Google rater determine quickly that a question is still unanswered if I don't have the word *solved* in the title" to which the answer is no(because that's not generally expected or in use).
An answer = good
An indication there is no answer yet = good
Saying solved when simply reading would tell you that = no benefit
Googlebot doesn't care but the raters do. This is actually an important topic for forum owners given that Google raters are instructed to answer the question.
NOTE: Allowing members to rate responses and floating the best responses to the top is apparently appreciated by Google raters, even on low quality pages.