Oh WOW I take it that this actually happened to you?   I have crammed for many an exam but never the wrong stuff I think I would actually have a cow come out my rear if that happened to me.  The closest thing I have to that is when I switched schools in the 3rd grade and on the first day we spent like and hour or something learning multiplication then the teacher hands us this quiz.  We had just spent time learning multiplication of numbers like 14X2 and the quiz and numbers like 1,452 X 250 and I tried my best (I think was in tears by the end of it) but I'm sure they were all wrong.  Well it turns out the quiz was addition not multiplication.  She let me retake it though and I did much better.

fightorace : Something similar, yes. Instead of  the usual 'A' I got a 'B'. Thank goodness...

I stopped cramming two years ago, but i can remember a time when this happened.

I was supposed to study trigonometry, but i would up studying other shapes, like rectangles, prisms, E.T.C. In the end, though, i managed to ac the test since i had miraculously remembered the material anyways.

Ouch! That hasn't happened to me...yet. I've underprepared and overprepared, but I've never done poorly from studying the completely wrong section.

What has happened, though, were quizzes over reading assignments I didn't know we had. That was middle school, and I wasn't the most attentive type. =P

I have never crammed for an exam. I couldn't do that to myself. I have studied something wrong in english as they don't tell you what is in the exam over here.

Naw, when I was in school, I never crammed for a test or an exam. Whenever I did do that, I would always focus on one thing, and forget the rest of what was going to be on the test. So, I always just winged it. I usually got a B, if not an A, on the tests because I actually payed attention in class, though, so there was that. 

Oh my god, I hate when that happens! I remember this happening to me a few times due to the teacher's fault though. One of my teachers gave me the topics to study for and when it came to the test, it was seriously nothing related to what was said. That was not a good feeling and i felt duped especially when I didn't get the grades that I deserved.

Yay for cramming though. T_T

I have found myself looking over things last minute, usually the night before, or even the day of. Thankfully I do have a study period to do that, but even still, it wasn't easy, and I just barely managed to pull of a good grade on the assignments and tests. I try to avoid cramming as much as possible because it is ineffective to try and process a bunch of information all at once, if its stuff like reading or memorizing, I try to stretch it out over 3 days or so, and I make sure I go over the material in the morning when it is fresh in my head rather than right before I go to sleep....

Recently I read the calendar for my AP Psychology class wrong and I read the wrong set of pages for the next class period, and when I found that out at the beginning of the class, I literally took about a minute to flip through the pages I was supposed to read and looked at the vocab and I still managed to pull of an 80 on the quiz. Thankfully this is the only time this has ever happened to me

Yes i've done this before ended up going somewhat well , but not the best either. Its not a very good idea in general.