Interesting paper about means of complex numbers (PDF).

is it the modulus?
\sqrt{42^2+93^2}=102.04
rest is just a phase and if it's a physics course, well then just ignore it.
damnit! it's more than 100!

Maybe it is the mos obvious way.
The overall score was 42+93=135 CR and he/she got 42 (real points) and 93 (imaginary points). So he/she has 42 out of 135???

It could have been worse: it could have been -42+93i.

You're overlooking it. The real component is the real grade. The imaginary component is just that, imaginary. So this student's score is 42, probably out of 100.

So, is the imaginary part just made out? Doesn't it come from any calculation related to the student's grade?

Me and my friend once had an idea for the math competition we've organized to give a score in complex number. Real part stands for advance problems that REALLY use the math. Imaginary part stands for problems with red herrings, traps, and nonsense stuff but still solvable. The winner is the one with the highest norm. (He might be very genius in math, or just very clever to avoid traps)