I don't think there is a set number as it can depend on which questions you get. If you get a bunch right in the beginning, the CAT will start giving you really hard questions.
The numbers I chose have no relevance at all to getting a 45+Q.
Scenario 1)
You start out like a rock star and get the first 15 questions correct. CAT gives you very tough questions. You miss 6 of the next 10. CAT doesn't hold it against you as much because it knows it gave you top-level questions.
Scenario 2)
You start out on a good pace and get 11 of the first 15 correct. CAT gives you intermediate questions. You get 8 of the next 10 correct.
Each scenario could still give you the same Quant score. The level of difficulty for the questions is different and that matters to GMAT algorithm for computing your score.
Vavali
Guys
What is the most amount of uestions you ould possibly get wrong on the Quantitative section to score a 45?