Very hard verbal questions: the highest-numbered SC and CR questions in OG. Unfortunately, RC questions are grouped by passage, so you don't know which are the hardest. For RC, inference and specific detail questions tend to be harder than main idea questions. "Minor" question types tend to be harder than inference and specific detail questions.
Some of the questions in our online questions banks are very difficult. You have access to those question banks if you are either one of our students or if you've bought our verbal books. We also have a workshop targeted at the hardest SC questions; they are not all 99th percentile, but they are all 90+ percentile.
I'm sure other companies also have collections of very hard questions, so you may want to ask the experts who represent those companies.
Inequalities + DS
Go back and look at some of these again. Figure out: what are these inequalities really telling me and what are they really asking me? For example, if I see something just with variables, I know that they're probably testing some number property theory. If I see <0 or >0 at any point, I'm pretty sure that the issue is a positive / negative issue. Same if I see absolute value with inequalities. If I see a DS yes/no question with just variables, I know that I'm probably going to need to try some different numbers to see what's going on. And so on.
So see if you can start to categorize certain types of inequalities + DS set-ups (eg, value vs. yes/no questions, or pure theory questions with no real numbers, etc) and what they should trigger you to do (in terms of setting up the problem). Literally make a list - if I see A, it probably means B, and I should try doing C.
Then start trying some new problems to see if you can execute on your new plans.
The 4th RC can certainly make a difference, just as any other RCs can. RCs typically mean 3 or 4 questions in a row, and we can't afford to make mistakes or give up on 3-4 questions in a row anywhere on the test.
So, one of the things you need to do is change your mindset. This test does not work in the way we'd expect things in the real world to work. In the real world, you'd have a lot more time to thoroughly examine some piece of writing, and then you'd probably be asked to write something yourself, or discuss the writing, not just answer a bunch of artificial, multiple-choice questions. So don't get sucked into thinking that just because they call it "reading comprehension," you have to read and comprehend it in the same way you would something you need to comprehend in the real world.
Have you seen this post before?
https://www.beatthegmat.com/verbal-strategy-t14035.html
It contains some detailed notes about how to approach RC passages and questions. Also know this: the notes you take should be specific enough for you to be able to answer any main ideas from your notes, but the notes should NOT be specific enough to be able to answer any inference or specific detail questions from your notes. Instead, for those, you should just be able to use your notes to figure out (quickly!) which paragraph is most likely to contain the information you need to answer the question. Then you go to that paragraph and learn what you need to learn to answer the question.
Finally, something that may help you with changing the "I must read this very carefully" mindset. For any given passage, about twice as many questions are written as are actually given to any one person. So, they may write 7 or 8 questions for a passage, but you'll only see 3 or 4 of them. This means that you are guaranteed not to get asked about all of the detail in the passage. Why learn it if you aren't going to get asked about it?
And you can actually get better by going back to RCs you've already done. Go look at your notes. Did you write down too much or too little on the first read-through? If you wrote down too much, what could you get rid of, in hindsight? If you didn't write down enough or didn't write down the right things, what should you have written down, in hindsight? (Again, remember: high level stuff should be written down; details should not be.)
Did what you wrote down actually match the points being made, or did you misunderstand anything on the first read-through? If you misunderstood something, why? What can you do next time to avoid that?
Could the stuff you wrote down actually be used as a credible outline for the passage - what someone would have written before they wrote a first draft?
Also, when we do stuff in OG, we see ALL of the questions - but that's not what we'd see on the test. Pick three or four of the questions randomly. How much of the total passage is covered by just those 3 or 4 questions? Prove to yourself that you
won't get asked about everything!