Top of the most advanced problems?

What subject/topic?

PS, DS, CR, RC, SC?

All of them. Let's say 5 tops.

Thank you all very much for your suggestions!

I think that the previous replies all made good points. AbhiJ answers your question specifically, and I agree with that list. I would, however, expand the math list to include the GMATClub tests and Jeff Sackmann's Extreme Challenge (I'll get back to this in a moment).

For verbal, LSAT is great for RC and decent for CR if you're looking for difficulty. For SC, the most difficult source that I know of would be the Brutal SC document. I didn't find it very helpful, unfortunately.

I'm generally a big fan of Manhattan, but its Challenge Archive is excessive. Many of the questions are way beyond anything from the GMAT, and that can be a bad thing. It's good that you want to push yourself, but don't do so for its own sake. Remember that the point of question practice is to improve your performance on the test. And in this regard, Manhattan's Challenge Archive is inferior to the GMATClub tests and Sackmann's Extreme Challenge.

The occasional Manhattan Challenge problem is okay, but these shouldn't be relied on exclusively - especially toward the end of one's studies. On a number of occasions, these problems would only frustrate me and I would give up and immediately look up the answer. I had to stop; that kind of passive and defeatist attitude would have caused trouble for me on the test. But that's just my personal experience. You may love them. The important thing is not find the "hardest" questions around per se, but rely on the questions that will allow you to reach your target score. Some might accuse that "advice" as a mere platitude. Fair enough. But in my experience, the simplest advice tends to be quite important when it comes to the GMAT.


And here's a review for Manhattan Challenge Archive:
review-of-mgmat-challenge-problem-archive-98677.html

I would recommend you to go to each of the topics sub-forums and you will find a question directory by topic and difficulty..... it is that easy.

I forgot to mention Ariel Goldberg's quant problems. A few members recommended his product.

See these links for more info:

https://gmatquantproblems.blogspot.com/

ariel-goldberg-s-quant-problems-100008.html

570-q30-v38-to-760-q49-v44-in-3-months-long-84094.html