How many first questions should be correct to reach 760+

I was curious to know that how many questions in starting of each section (Verbal and Quant) should go correct to reach the maximum difficulty level of GMATPrep application' algorthim. For Instance, If one does question number 1 to 13 in verbal section correct so will the 14th question is likely to be the most difficult? Can anybody, who scored around 760, post that how many first questions were correct in verbal to get 44 or 45 in Verbal section.