If someone answers multiple questions that get merged together later on, Quora will display the top answer, and will collapse the others as duplicates. The collapsed answers can still be accessed at the bottom of the question page in the collapsed answers section.
If you're the author of one or more answers that got collapsed due to a question merge, you can a) leave them as-is, or b) delete the ones you don't want to keep. If you delete your top answer on the page (e.g. the one that's currently visible), your next top answer will move out of the collapsed answers section and become visible.
If you want to learn more about question merging, please see: What's Quora's policy on merging questions?