710 and 600 score with the same number of incorrect answers?

Hi, I took the first practice test two weeks ago and it was 710. Today I took the other one and it calculated the score as 600, although there is almost the same number of incorrect answers in each section. (1- V 12 Q 6 incorrect, 2- V 13 Q 5 incorrect) I know there is an algorithm and it calculates the score on a different basis, but I don't comprehend how such a range could occur? What could I do to perform as the first practice exam?

Thanks in advance