Hi Schachfreizeit.
The issue is that, while some types of questions are more likely to show up on test day, you could see practically anything on your quant section.
For example, on one GMAT, I saw two or three triple overlapping sets questions. Recently, someone reported seeing multiple Evaluate the Argument questions on the verbal section. So, it's tough to game what you should work on.
That said, some topics you for sure want to be strong in. Number Properties is one. Another is Root and Exponents, partly because roots and exponents are involved in answering multiple types of quant questions. Another I'd work on is Quadratic Equations since they can be used in multiple types of questions. Inequalities show up in multiple types of questions as well, and by working on inequalities, you'll also be working on algebra. So, Inequalities and Absolute Value is another good one.
Also, becoming better at algebraic translation helps a lot.
Other than those, you could work on whatever you're weakest in.