You are a human, not an AI. You know whether your idea seems related to the solution. The AI has thousands of ideas and doesn't know which are better. Graders shouldn't accept a thousand guesses grubbing for 1 point.
If verifying a good idea is easy, then the evidence shows that the AI didn't have good ideas for the other 2 problems.
If verifying a good idea is easy, then the evidence shows that the AI didn't have good ideas for the other 2 problems.