1. The Nerd that knows everything – They studied for hours and know every single thing But  they wont tell you a single answer…. You can have a "calm chat" with them later.

2. The Nerd that thinks he knows everything- They studied ..for like 20 min and think they studied the whole day, but in fact they don't know much and they'll get a low mark and then blame it on "bad luck" or "this question made no sense" (when it actually did but they need something to blame their bad mark on)

3/4. The I didn't study i don't care- there are 2 groups of these people the first one doesn't really care what grades they get  and the second one (sigh ) the ones that want to seem cool ..but really isn't but an excuse is "oh i don't care"

and finally 

5. The one that didn't study but gets high grades- we all have a person like that sometimes it even turns out to be me , like i don't study but what kapowww A from science , sometimes it even amazes