Every gdn teacher in the world knows that, or at least should know. It’s next to impossible to create tests that would measure understanding, and actually using that kind of tests in real life would be so time-taking and slow that schools and universities would grind to a halt.
As notabot below says, homework (and exams) are for the student. The “measuring” aspect in them gives only a sign that the student should note and act on (and of course, the society being what it is, the “measures” are also used in other ways whether we like it or not).
It’s tRump. He probably has the codes written in a post-it note that’s attached to his bedroom TV frame.