WA@ylm3575
Around 5 hours, the main change I did was I started to solve questions of 605-655 lvl on the GMAT CLUB, and the main focus while giving the mock was to get my first 5 Questions correct in all sections
My recommendation would be to approach it from a topic standpoint vs. difficulty and do ALL difficulties by Topic vs. some difficulties across. (take fractions only and do 10 questions of mixed difficulty; if you can get 9/10 correct, move on to the next topic). If NOT, then go back to whatyou are using to study fractions and review.
It is possible to do both ways however, but the topic is much more controllable and also more manageable to my compartmentalized mind. (e.g. my fractions are awesome and my probability is crap) - I can live with that because I know where i need to focus but I can’t live with it if it is too vague and I can’t see the enemy.