How to identify hard Quant questions?

I would suggest focus on 600 level questions and understand the logic/pattern used in each question type.

If you are taking more time during a GMAT Like questions, then the only option I could see at this point of time is try to "decode" every question type and then solve it.

Thanks

Alright - I will do so. Thanks for the help

I don't think you necessarily should try to identify hard questions in under a minute. A minute is how long you'll sometimes need to read and understand the problem. You won't know whether it's too hard for you or not until you've finished reading/understanding. So, there's nothing wrong with spending a minute. The trick is to move on immediately if you don't have a reasonable plan to solve the problem after you've spent that minute. There isn't much time on the GMAT to just mess around with a problem, trying to figure it out in different ways that might or might not work - you need to be able to read the problem and essentially know how you'll approach it. (That's not something that comes naturally, by the way! It takes a lot of practice, but you can get there.)

In short:
- It's okay to spend 1 minute on any problem (unless you're using a strategy that involves skipping some problems without really reading them, which is fine and can be a good way to recover from being behind on time).
- During that 1 minute, you should read the problem thoughtfully and consider whether you know how to solve it.
- You don't have to have the entire solution in your head at that point, but if you don't have a fairly good idea at that point how to approach it, you probably aren't going to 'make it up' in the next minute. So, go ahead and move on right then.

Günther,

I worry that you are on the wrong path for prep. Your comment that you will spend 10 hours each day for 10 days practising worries me. This is the wrong strategy. The GMAT is not like doing push-ups. You cannot just do 1000 GMAT problems to develop your GMAT "muscles" and score 600 on the test.

The real problem is either that you do not understand the problems you are encountering or that your understanding is very superficial.

When we went to school, the teachers sat us down and showed us a problem. The teacher taught us the one "true" way of solving this problem. Perhaps she did 2 or 3 on the board. Then she wanted you to solve a problem using the method she had showed you. You had to show your work so that she knew that you were using the method she taught and so that she could diagnose errors in the process. Then you had to do the same method at home (homework) until you could do it by heart.

In other words, the teacher installed in you a default solving method (DSM). The GMAT problems that you find hard are those that are resistant to your DSMs. Maybe your DSM works, but it takes 5 minutes. Maybe your DSM works, but you are so used to solving for variable one that you get confused when the problem asks you for variable two. Maybe your DSM just doesn't work at all.

By reading the Manhattan books, you have attempted to replace the DSMs that your school teacher gave you with MGMAT DSMs. Manhattan DSMs are better, but they're still DSMs. You have 15 or 20 new DSMs in your brain, and you are trying to figure out which DSM will solve the problem at hand with no deep comprehension of which DSM to use, why the DSM works, or the pitfalls along the way.

You hope to overcome this incomplete comprehension through rote practicing. This is unlikely to be successful.

It would be far better for you to take one of these problems that you can do and to explain it to yourself as though you were teaching a young child who was seeing it for the first time. Explain why the method you are choosing works, possible challenges in implementing it, and how to know when to use or not use it.

If you teach one concept a day and have 15 concepts to teach, you will be done in 15 days. By teaching it, you will come to a better, deeper understanding of the problem and the solution.

Hi Elias

Thanks for your reply and all the information.

I don't rush through the methods. Once I've learnt a DSM I try to understand how it works. I don't just exchange numbers or variables. Probably, I would be able to explain most of the methods I've learnt to a small child. Moreover, I am able to solve almost all Problem Sets at the end of MGMAT without only 1-3 errors (out of 10 questions) and those problems also vary a lot.

However, I am quite good in solving questions when I know what concepts are being tested (e.g. Algebra, inequalities, percents, fractions, number properties etc.). But if I get attacked by 37 Quant problems, I am don't have this mental orientation at hand and I don't know how which concept is right for the question.

My plan now
I think it wouldn't make sense to review the methods in the MGMAT book again as they are quite clear to me. I've just taken a free GMAT Club Quant CAT and will now focus on the weak areas. I will do so by reviewing and practising 600 level questions here in the forum so that I get used to work with the same methods on different questions.

Do you think this approach makes sense?

Furthermore, in the Quant CAT I had 14 correct answers leading to a Score of 8 with 5 percentile - how could this be possible? According to my research you should have a higher score if you correctly answer almost 50% of the questions?

Thanks!
Günther

Günther,

My point was broader. Many prep companies offer a "When you see X do Y" preparation. This is not necessarily bad. However, this approach leads to plateaus and ceilings on performance.

We believe that it is important to adopt a beginner's mind when you approach a problem under prep circumstances. Treat the problem as though you had never seen a problem like it before. Think of new, creative ways to attack the problem. Don't be afraid to fail. The idea is to fail quickly and then move onto a better solution path.

I have yet to see a problem that could only be approached in one way. Let me illustrate what I mean.

Imagine that we have a very talented mathematician who can do everything in math except for one thing: Because of a head injury, he no longer remembers how to multiply by 8. He can still take 8 and multiply by 4, but he cannot take 4 and multiply by 8.

Today he has a problem: He needs to figure out how many squares there are on a chessboard. He sees that the chessboard is 8x8, but he also knows that he cannot multiply by 8 because of his head injury.

What can he do? Well, he can simply add 8+8+8+8+8+8+8+8 = 64, but that will be slow. Is there a better solution path?

Well, he can divide the chessboard into top and bottom. He can literally take a saw and cut the board into two 8x4 sections that he will glue together to make a 16x4 area that he can calculate.

Or he can divide the board into quarters. He will have 4 squares of 4x4 for 64 squares.

Or he can cut off the two top rows and paste them onto the side so that it makes a 6x10 area with a 2x2 area left over. 6x10 = 60 and 2x2 = 4 so 64.

Each of these techniques could teach us something about a new way to approach an old problem. For example, if you were asked to multiply 36x15 you could probably do so. Or you could take the mathematician's first idea and cut the 36 into two 18x15 areas that you will paste into an 18x30 area. Most people find it easier to multiply 18x30 than to multiply 36x15.

Or what if someone asked you to multiply 98 x 92? You could take the mathematician's last idea and chop off two rows to make it 100x90 with a 2x8 area left over. 9000 + 16 = 9016.

Each of these techniques could, potentially, be useful in an unrelated area. If, for example, the problem required you to calculate 17^2 and your teacher told you to memorize the perfect squares, but you never did... you could still chop off 3 rows to make it 20x14 with 3x3 left over. 289

My point is this: Get away from DSMs. Approach every preparation problem as though you had never seen a problem like it before. This will teach you the skills you need to handle problems that you have never seen before when you take the real test.

If you're solving questions from the OG, then gmatclub has OG guides that tell you forehand the difficulty level of questions. You can use that as your guide. However it is advisable to solve a mixed bag of questions(in terms of difficulty and content) and solve them at length i.e at least 25 questions in one sitting...so as to simulate the actual test.

Hi Günther,

Since the GMAT is a no calculator test, quant questions are either designed to have nice numbers, be solved with estimation, or solved without calculations (more so in DS).

If you are solving easy/mid problems in 3-4 minutes and getting them correct, that means that you can shave off 60-90s per problem just by improving your arithmetic skills and taking more efficient approaches to solve quant problems. Given your timeframe, I would start by working on your arithmetic with strict time limits in place.