What should I do if my professor changes the question mid-exam? I was writing a 3-question examination today (undergrad) with 1200 other students when our professor comes in after ~2/3 of the exam and changes a question to make it solvable. This was a 1.5 hour exam where each question was designed to take 30 minutes so unless you did the other two questions knowing that question was impossible to solve and waited for an announcement on instructions of how to solve, you would not be able to finish. When I walked out of the exam, you could tell that everyone was mad that this changed question could have impacted their overall mark by 15-20%. What should I do to help out myself and my fellow classmates who were screwed over by this change? Has anyone ever had a similar situation?
This does happen sometimes, despite a professor's best efforts to check the exam beforehand.  Professors are humans and make mistakes.

You can write a polite email to the professor (or whoever is in charge of grading the exam, if different), letting them know that you feel this had a disproportionate negative impact on your score.

That's about all you can do.  It is ultimately up to the professor (or grading committee, etc) to decide what to do about this issue, if anything.  They might:


Do nothing, reasoning that although the correction was unfortunate, it affected all students equally.
Give credit to students who made an appropriate attempt to solve the impossible version of the problem.
Adjust the "curve" or other statistical correction of the exam score to take this into account.
Discard the question's score, and reweight the scores on the other questions.
Discard the entire exam and hold a new one.
Discard the entire exam and reweight other exams in the course to compensate.


In principle, if you don't agree with the professor's decision, you may be able to appeal to some higher authority.  This would depend on your university's regulations, and my guess is that it would be unlikely to succeed, if the professor did anything halfway reasonable. I'd consider that any of the above options would satisfy that.