[emmender1]

prompt-engineering to get the answer is analogous to prompting the fortune teller to tell your future - ie, you have an intended answer that you expect (or wish for in the case of a fortune teller), and you tweak the prompts to get there.

[Smaug123]

Well, you might not know the answer, even if you know some properties the answer must have and some processes that might lead to the answer.