It doesn't work like that. First, there are two parts of 125 questions so the total is 250, not 300.
Second, some of those 250 question (I don't know exactly how many) are for evaluation purpose and are not counted in the final score, so it doesn't matter what your answer was.
Third, the score is calculated out of the remaining questions and its relative between 0-150.
To make it simple, if for example, everybody answered everything right then everyone will get a 75 score and not 150. On the other hand, if only one person got only one question right and all the others answered everything wrong, then that person will get 150.