While on a question’s page, use the button called “Answer this question” right under the question’s description. Or, you can click directly in the text area situated below the answers zone and enter & submit the answer.

An alternative way of answering a question is by email. Supposing you receive a question by email (because you subscribed to its author's activity, or to an associated tag), you can answer the question by simply hitting the “Reply” button in your email client, typing the answer, and clicking the “Send” button. Your answer will be injected into Quandora as if it was submitted using the native interface.