Not OP, and I don't think it directly indicates how smart you are, but it does show you are at or above some smartness threshold (i.e. smart enough to get the a

Not OP, and I don't think it directly indicates how smart you are, but it does show you are at or above some smartness threshold (i.e. smart enough to get the answer). If you don't get the answer, you might still be above that smartness threshold, but didn't get it for some other reason (didn't have time to study, didn't sleep enough the night before, interview anxiety, etc.).