Oh, man, I recently dug out one of my 7th grade tests from the loft, we were supposed to be getting rid of old papers and tests but me and my brother could not stop laughing at this one question... meh. This is what it said:
Spell Mississippi.
I circled 'Mississippi' and wrote 'idiot' in red pen next to it. I can't imagine how I got away with that.
Another infamous answer I discovered was from the same test. The question was:
Sihad has 20 marbles. If his mother gives him 15 times the amount of marbles he already has, how many is he left with?
My answer was:
Sihad's momma is a big fat slut.