Articles published in Challenge Problems

GRE Quant Best Practices: Improving Problem Recognition

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A number of students have recently told me that they struggle with “problem recognition,” particularly in the Quant section of the GRE. What many mean by this is that when they look at a problem, they don’t immediately see how to get to the solution. They might recognize some of the concepts involved, but the problem as a whole has aspects that make it look unfamiliar and difficult. When this happens on the test, in a high-pressure, time-sensitive environment, the resulting feeling can be paralyzing. Read more

GRE Quantitative Comparisons: The Equal-Different Method

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There are many different approaches to tackling GRE Quantitative Comparisons problems. One of my favorites is something that, in my opinion, generally doesn’t get talked about enough. This method is for people who feel very comfortable with the basics of quantitative comparisons, and have a decent handle on mental math. When executed properly, it can save you a great amount of time on the test, thus giving you the opportunity to solve other problems. It also can help avoid making silly errors by reducing the number of paper-and-pencil calculations you have to do. This method is called the Equal-Different, or E-D, method. Read more

Careless Mistakes on the GRE: Go Slow to Go Fast

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It’s okay to make mistakes on the GRE. You can miss plenty of problems and still get a great score. However, it matters why you make those mistakes. Miss a problem because you don’t know how to solve it? That’s totally okay (as long as you don’t waste too much time). Miss a problem because you added two and three and got six? That’s a problem, and here’s how to fix it: stop trying to go fast. Read more

De-Tangling Difficult Word Problems on the GRE

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Let’s start with a problem that’s been giving my students trouble recently. Read it through, but don’t try to solve it—yet.

GRE Interest Problems

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Interesting Interest

Deposit money into a savings account and you will earn interest. Rack up a bunch of charges on your credit card, and you’re going to be charged interest. In the real world, the bank takes care of calculating interest for you, but if the word “interest” shows up on the GRE, you’re going to need to know how to calculate it yourself. Read more

More Fun with GRE Variables

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In my last blog post, we practiced using variables to solve Quant word problems—and we solved some problems without using variables, too. The big takeaway: you don’t have to start every word problem with a tidy little list of variables and equations! It’s okay to focus on the numbers in the problem first. However, variables are sometimes the key ingredient to getting a GRE problem right. In this article, we’ll try using variables to solve some tougher GRE Quant word problems.

Here’s one of my favorite problems from the 5lb. Book of GRE Practice Problems. Give it a try before you keep reading: Read more

GRE Math for People Who Hate Math: What Is a Variable, Really?

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Imagine a world where every conversation went like this:

Student: When is our final project due?

Professor: Three days after the first Wednesday after your rough draft is due.

Student: What?

Professor: The rough draft is due 15 days after the date 6 days before May 14.

Solving a GRE math word problem is a little bit like having this kind of conversation. That’s why word problems can be so infuriating. The problem isn’t lying to you. It’s just telling you the truth in a really annoying, backwards way. (Reading Comprehension problems do that too—it’s not just a Quant thing.)

In the conversation above, how would you work out the due date of the final project? Personally, I’d start by getting out my calendar. I’d start at May 14, then count 6 days backwards. Then, I’d count 15 days forwards, put a star on the calendar, and mark it ‘rough draft.’ Then I’d find the first Wednesday after that date, and finally, I’d count three days forward from there. That would give me my answer. Read more

Solving GRE Problems in Multiple Ways to Build Flexibility

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Recently, my colleague Tom and I decided that, since we were teaching in adjacent classrooms, it might be fun to combine our classes and co-teach a lesson. Tom and I have very different strengths, both as test-takers and teachers. I love algebra, and I’ll always seek out an algebraic solution to a problem (even when this might not be the most efficient method—my strength is also a weakness). Tom prefers non-algebraic methods, like drawing diagrams or picking numbers. And our strengths inform what we emphasize in class.

So, for our joint lesson, we chose a number of GRE problems that could be solved in more than one way, and then took turns demonstrating each method. First, we each used the method we preferred (algebra for me, picking numbers for Tom), and then we switched and demonstrated the method we were less comfortable with. Here’s one of the GRE problems we used: Read more

GRE Percent Change Questions

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One of the most common mistakes many students make on the Quant section of the GRE is to misread percent questions, especially ones that ask you to calculate percent change (i.e. increase, decrease, more, less, greater, discount, or profit). You can fix this issue with a bit of practice, but it requires some careful reading on your part. Read more

How to Really Remember a GRE Vocabulary Word

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Think about your least favorite GRE vocabulary word. You know the one—every time you see it in your flashcards, you get that sinking feeling of dread. You always get this one wrong. You know it’s important, but for some reason, it just won’t stick in your head.

Okay, do you have a word in mind? Let’s conquer it—right here and now. Read more