It’s probably 40%, but that’s only assuming the people who paid attention the day before got a good night’s sleep and were able to focus, assuming that the people who did not pay attention didn’t know the material, and so on. There are hundreds of random but likely things that could happen.
There was a Big Nate strip, I don’t know which one, where he says that all of his (Nate’s) characters are the same with different hair. That is true in most strips, including this one.
Left to right, top to bottom: Gandalf, Aragorn, Boromir, Legolas, Gimli, Pippin?, Merry?, Frodo, Sam?