The best number of FAQs on a page can depend on several factors, including the target audience, topic complexity, layout, and more.
If you are creating a separate dedicated page for FAQs, then you should have at least 10 questions on this page.
However, if you have written an average blog post of about 1500 words and want to add a short FAQ section at the bottom, then you can just add about 3-5 FAQs for your users.