Can you understand your chemistry teacher's explanation of how to do an experiment? Then it's explicable, able to be comprehended clearly and accurately.
Since the 16th century, the adjective explicable has been used for things that are intelligible or that can be solved. It comes from the Latin explicabilis, "capable of being unraveled," and its root, explicare, "unfold or explain." These days you're most likely to find it in academic or formal writing, not always the most explicable of genres.