MGMAT (and the other tests) have their internal proprietory scoring algorithms to score. The one used by GMAC is not known to any other party.

Now coming to your question, the verbal and qaunt score of 36 and 35 is the score for that section. The one in % refers to the percentile which indicates where does your score stand when compared to others who take the exam. This percentile is based on averages caluclated by GMAC periodically. Now your score of 600 is a scaled score based on your individual verbal and quant score. Again this is based on table published by GMAC. I am not aware of the actual algorithm behind this calc. The score you see a % for the total score is again the percentile indicator for the total score. This precentile is not directly dependant on the individual section scores. So you cannot expect them to be average of the two.

To give an example if you score 49 on quant you will be in 89 percentile but a 42 on verbal would give you 92% I guess. This means that many people score lesser in verbal than quant. This score combination of 49 and 42 would given you a scaled score of 740 which is a 97th percentile.

Hope I was able to address your doubt.