How do I overcome my lack of focus for the GMAT?

As a reference point, many years ago I scored 750 on the Total Scaled Score of the GMAT, on a 200-800 scale.My advice to you is: sleep.  Sleep 9 hours a night.  10 if you need it.  That extra hour or two of study per day will do you no good whatsoever if you are so tired that you are just plugging away under a