For A, since a correct answer is worth 2, and an incorrect is worth -1/2, it is simple multiplication

30*2=60

-1/2*5= -2.5

Subtract 2.5 from 60

60-2.5=57.5

In total, that leaves 57.5 points.

For B, I would have to say it is not possible to determine the score based off correct answers, due to the fact that incorrect answers deduct points, and unanswered aren't worth anything.