See its pretty simple.............I will tell you the way I did and scored Q51 in gmat
Just work on some 10-15 quesns for each topic that you are not confident about in order to get yourself a brief IDEA about it and get your blood going....
Go for MGMATs in proper timed conditions even if you end up scoring 43-45,,,,no issues
For
GMATCLUB tests do the same as well.......practice under timed conditions and try to get more than 26 correct....(except for tests number 7-9....these 3 are horribly tough)
Once done revise in your untimed conditions and try to solve them........
Once through revise once again the same questions (specially those you got incorrect) till you get all concepts cleared..
I affirm that you will score 49 or more in real test......trust me you dont need apart from
GMAT club tests,
MGMAT and Gmatpreps.............
Remain calm during exam to avoid silly mistakes and hurray MISSION ACCOMPLISHED !
Good luck to all......