Hi scholesy,
I’m glad you reached out, and I’m happy to help. To reiterate, your GMAT score is based on not only the number of questions you answer correct/incorrect, but also the difficulty of those questions, among other things. Thus, it’s likely that on practice test 4, you got a few “lower-level” questions wrong, and that is what resulted in your Q46.
Regarding your timing strategy, you need to be really careful about blindly guessing on quant questions in order to pick up time during the exam. If you have too quick of a “trigger finger,” before you even realize it, you’ll have guessed on 5+ quant questions, and then what will happen to your score, right? Thus, you may consider taking a more organic approach to solving GMAT quant questions. In other words, your goal should be to correctly answer as many quant questions as you can (all the while keeping an eye on the clock).
To know when to give up on a question, you need to trust your instincts and follow your internal clock. For instance, let’s say you are 2 minutes into a question, but you know that you are on the right path; in that case, you’d want to keep going even if you would need 3 minutes to answer, right? After all, if you have fully mastered GMAT quant, then you should be in a position to answer some questions in 30 seconds, and thus it’s OK to spend more than 2 minutes on certain problems. On the other hand, say you are 60 or 90 seconds into a problem, and you know that you are going down a rabbit hole and likely will not be able to correctly answer the question. In that case, take an educated guess and keep things moving.
My overall point is, yes, it’s OK to guess, but ensure that you take a strategic approach to how and when you guess.
If you have any further questions, feel free to reach out. Also, you may find it helpful to read this article about
timing strategies for a higher GMAT quant score, which discusses various aspects of quant section timing, including guessing strategies, in great detail.
Good luck!