It's a Large Language Model. It doesn't "know" anything, doesn't think, and has zero metacognition. It generates language based on patterns and probabilities. Its only goal is to produce linguistically coherent output - not factually correct one.
It gets things right sometimes purely because it was trained on a massive pile of correct information - not because it understands anything it's saying.
So no, it doesn't "guess." It doesn't even know it's answering a question. It just talks.