Hi woohoo921.
You can score 46 in quant with up to 13 missed counted questions. So, theoretically, you could guess on 13 questions and still score 46 in quant. Also, there are 3 experimental questions in the quant section that don't count at all. So, if you somehow guessed on and missed the 3 experimental questions and the 13 hardest counted questions, you could still score Q46.
Of course, as you said, there a good chance that you'll miss some questions you don't guess on. Also, there's some chance you'll guess correctly on some guessed ones.
Let's be safe and shoot for 11 missed quant questions, including one missed experimental question. Say you miss 5 that you answer and guess and miss 6. So, you could guess on 6 quant questions and achieve your score goal as long as they are not easy questions. If you want to be safer, don't hope to guess on an experimental question and guess on 5 max.
You can score 39 in verbal with up to around 10 missed questions. However, it's more common for people to score V39 with 6 or 7 missed counted questions. There are also 6 experimental verbal questions. So, let's say that you miss 4 counted verbal questions that you answer. In that case, you can guess on 2 or 3 of the hardest verbal questions and 1 (hopefully) experimental question and score V39+. If you want to be safer, don't hope to guess on an experimental question and guess on 3 max.
Key to all of this is guessing only on questions you find difficult because, if you randomly guess on questions and some of the ones you guess on are easy questions, you'll drag your score down significantly because the test dings you pretty hard for missing an easy question.