How to break quant plateau for GMAT retake in 1 month?

I am going to talk about things you probably already know. But trust me, if you focus on following 3 issues and you should score at least 48-50.

Problem 1: Lack of complete knowledge

1) You said that you are facing difficulties with 700-800 level questions. I hope you know all the basic formulas/methods/topics in maths. For example : Formula of area of trapezoid, surface area of cylinder or cube, basic permuntation and combination, compound interest ratesetc. If not, learn all the tougher formulas as well - there are hardly 10-15 of them - and they are not really tough

2) Practice few tough problems on these assumed to be tough concepts.

Problem 2: Silly mistakes and traps

3) You sure are making silly mistakes: read complete question, question stem and options - take few seconds to figure out whats being asked and whats given - avoid silly mistakes. Sometimes we misinterpret the questions and find them too easy. For example you solved the question right but missed the part where it said that "X" is a "Positive Integer". Be slow at such easy questions make sure you are not missing anything.

4) You sure are missing traps: Most of the times the question itself is easy but we couldn't figure out how to solve it. Remeber that the questions is indeed not tough. Collect all your knowledge about the topic, retry and if still stuck - move on.

Problem 3: time management

5) Don't spend more than 3 minutes on any questions. If you haven't got it till 3, chances are you will not get it - move on.