How to use 21st Night to study for the GMAT

by Trevor Klee, Tutor

tl;dr: do questions from the Google Sheet and from GMATPrep tests. Any that you get wrong go into 21st Night. You’ll find explanations online.

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1. Your overall process to start preparing for the GMAT

a) Start with a diagnostic test. What are your specific strengths and weaknesses?

Put your incorrect questions into 21st Night, then discern the patterns using the filter screen. What are you getting right and wrong?

b) Do questions to focus on your weaknesses from this Google Sheet. Explanations are included.

Put any questions you get wrong into 21st Night, along with explanations.

Don’t worry about speed immediately, that comes with being confident and fluent in the techniques. As the old Army saying goes, “Slow is smooth and smooth is fast.” Focus on being smooth in your application of techniques.

c) Once you feel like you’ve covered your initial weaknesses, or you feel confused about about what to do next, take another practice test. Then start with a) again.

d) There are two parts to studying for the GMAT.

One part is like being a marathon runner. You need to put the miles in on the pavement to run a marathon. Anyone can do it, but it takes effort.

Doing questions and putting them into 21st night is the equivalent of putting those miles in. It’s going to suck, but that’s how you learn.

The second part is like being your own coach. You need to reflect on your own progress and what you get wrong and right.

21st Night can help, but you still need to ask yourself: what are the patterns in what you get wrong? What techniques do you have difficulty applying?

2. Your materials to prepare for the GMAT


-Official GMATPrep tests

-Official Guide questions, categorized as laid out in this Google Sheet.

-21st Night


-Strategy guides, for the necessary techniques

-My recommendations: my strategy guides, Manhattan’s

3. Your GMAT study plan

-Generally speaking, you need to work 100 hours (intelligently) to improve 100 points on the GMAT. This is, of course, a very rough estimate, and depends heavily on the quality of the hours you put into studying.

-A reasonable way to accomplish this is to plan to work for 20 hours a week for 2 months (giving yourself room for breaks and slow days).

That means working 2 hours per day on the weekdays, and 5 hours per day on the weekends.

-Studying for the GMAT should be a sprint. If you plan to spend 6 months, you will get demotivated midway through and lose track of what you’ve learned.

Make it a major part of your life for 2–3 months, then be done with it.

-For a specific 60 day study plan, you can check out my email course.

4. How to review the GMAT sections

-This is both how you should approach the questions, and, more importantly, how to analyze a question you got incorrect

-Revision through the error log is the key to learning

Reading Comprehension: what precisely did I need to read to get the correct answer?

Critical Reasoning: how does the argument work (premise, reasoning, conclusion)? How does the correct answer fit into the argument?

Sentence Correction: how does the correct answer correct and efficiently convey the meaning?

Problem Solving: what equations do I need to start with? how do I get from there to the answers?

Data Sufficiency: How do I simplify the prompt? Or, in other words, what’s the prompt really asking for?

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