Regrades and broken questions
We try to write questions with no errors and to grade with perfect accuracy. But, of course, we are only human. Mistakes happen and need to be corrected.
I haven't submitted the problem yet, but it's clearly self-contradictory (or otherwise broken)!
While our questions are sometimes broken, the vast majority of the time the question's fine and you are misreading it. It's not too late to figure out what it really means and get it right! Read it again, and make sure you're spending at least as much effort trying to figure out how you could be wrong as you spend trying to explain to us why we're wrong. (Though sometimes the latter is a good way to do the former - write out very explicitly why we're wrong, and then review your argument critically, looking for the weakest point.)
If you still think it's wrong and it's a homework question, talk to us in office hours or Piazza. If it's an examlet, then take your best guess.
I submitted the problem, and disagree with the grade I received (either the grading or the question seems wrong).
First look over the model solution and try to figure out on your own what went wrong. If our solution doesn't make sense, talk to us at office hours rather than submitting a regrade request. If after the previous steps you want to submit a regrade request, go to the question on PrairieLearn and click the "Report an error in this question" button. If the issue is with your grade rather than with the question, start your report with the words "Regrade request:", and then tell us why the grading is incorrect (we don't accept just "regrade request", "please look at this again", etc with no explanation).
Regrade requests must be submitted within one week from when we post grades for the assignment. We don't guarantee that late regrade requests will be considered. If you have a compelling reason why you couldn't submit the request on time, please include the details in the request.