Great job! I know you want an even higher score—but you did do a great job already to get from 520 to 640.
On verbal, the key is to pinpoint where in the process you're having trouble. For RC and CR, it could be any or all of the following:
(1) Reading / understanding / analyzing the text (the passage or argument). Do these things happen?
-- You have to re-read part of the text because the first read didn't make sense to you
-- You realize after looking at the explanation that you misunderstood what the passage was saying (you thought it said X but the explanation makes you realize that it really said Y)
-- You see a vocab word that you wouldn't feel comfortable using yourself (not including technical terms), or you have to look up the word (this is for RC, mostly)
For the first two, try this:
After reading an argument or a paragraph of a passage, summarize the main idea of that text—in your own words and aloud. Pretend you're telling a friend about what you just read (but s/he hasn't read it). You might even try this for real with a friend or family member who you think is good at reading / comprehending advanced text. After you've summarized, have the person read the same text and then tell you whether, in their opinion, your summary missed anything significant. (Reminder: Main idea. The goal here is not for you to memorize and list off all of the details. Just big picture / main messages.)
For CR, add this. Who's the person in your life with whom you most enjoy arguing? (And, in particular, you really love to win the argument...
) When you read a CR argument, pretend that person is the one making the argument. You're immediately trying to analyze, pick apart, attack! Well, did you think of ABC? Wait, a second, you're just assuming that XYZ is true! In other words, when you're reading an argument, you're analyzing it critically every step of the way, looking for the flaws and holes. When you're summarizing it aloud, include those weaknesses / flaws / potential holes.
For the third, you may need to do some vocab study. Vocab isn't explicitly tested on the GMAT (as it is on the GRE), but RC in particular does use grad-school-level vocab.
Also, for RC-type reading, the Economist may be a bit too casual / mass audience for these purposes. (And even a lot of Scientific American is as well.) Take a look at this article for ideas for other sources of university-level / academic writing:
https://www.manhattanprep.com/gmat/blog/how-to-improve-gmat-reading-comprehension-skills/Next, the issue could be your analysis as you try to answer the question. Are you:
– correctly identifying the question type?
– adjusting your analysis depending upon the specific question type?
As an example, a CR Find the Assumption and a CR Strengthen are very closely related—but they are asking you to do different things. If you're not *very* clear on what kind of analysis you need to do, you're a lot more likely to fall into a trap.
Here's an argument: We sell one thing, widgets. In order to increase our profits, I propose that we lay off all of our salespeople who had below-average sales in the last quarter. That way, we'll have only the above-average performers, so our sales should improve.
What am I assuming?
Lots of things, but here's one: The salespeople with below-average sales last quarter are reflective of below-average performance in general. (But maybe our best-performing salesperson had below-average sales last quarter because her customers bought a ton in the quarter before that.) In order for my plan to work, it
must be the case that the stats for the last quarter are representative beyond just that one quarter.
What would strengthen this argument?
The salespeople with below-average sales last quarter have all been with the company for at least 5 years.
This time, this fact does *not* have to be true in order for my plan to work. A strengthener just has to fit this requirement: IF this is true, it will make the argument at least somewhat more likely to be valid. And, indeed, if it's true that these salespeople have been with the company at least 5 years, then this (slightly) strengthens the idea that I should lay them off. They've had lots of time to learn the product, build relationships, etc. If they were all hired 1 month ago...that totally changes the story.
As assumption must be true in order for the argument to play out as planned. But a strengthener just has to make the argument a little more likely to be valid—it does not have to be true. If you're not making that distinction as you try to answer the question, you're more likely to fall into a trap.
Finally, of course, the answers themselves can be very tricky. When reviewing / analyzing problems, ask yourself:
(1) Why was the wrong answer so tempting? Why did it look like it might be right? (be as explicit as possible; also, now you know this is not a good reason to pick an answer)
(2) Why was it actually wrong? What specific words indicate that it is wrong and how did I overlook those clues the first time?
(3) Why did the right answer seem wrong? What made it so tempting to cross off the right answer? Why were those things actually okay; what was my error in thinking that they were wrong? (also, now you know that this is not a good reason to eliminate an answer)
(4) Why was it actually right?
Do this anytime you pick a wrong answer, of course, but also do it even when you get it right. What was the most tempting of the 4 wrong answers? Analyze that. (If you knew outright that all 4 wrong ones were definitely wrong, that's fine. But often, there's at least one wrong answer that's somewhat—or really!—tempting. So even if you get that problem right, still go back to analyze why you hesitated before crossing off that answer.)
It's not easy to do what I'm describing above, but you've done a lot of great work already to lift from V18 to V28. The chances are good that you can do this too—it will just take some time and effort. Try that out and come back to let us know how it's going.