If you want to answer a question, you have two options:
(1) (a) to answer now by clicking on the button bellow the question
(b) to answer later by clicking on the button bellow the question
(2) (a) Now an input form appears where you can write your answer:
(b) If you chose to answer later, a link to the question would appear before the list of the quesitons.
In order to reach the list of questions, choose "Questions and Answers" from the drop-down menu in the options area (left column).
Click on the question to answer and proceed as step (2)(a)
(3) Click on "publish" and your answer will appear in the list bellow the question