To break through the average-difficulty GMAT problems and succeed on those upper-level separate-the-700s-from-the-Sixers items, you need to accept that the harder problems offer a unique challenge. They are not typically concerned with more obscure information in the way that Jeopardy-style trivia questions get harder the more obscure the information is. Instead, they challenge you to think more critically about the same fundamental skills that you have mastered in the middle-range problems to even get to that top-shelf point.
The key to success on hard GMAT problems is to accept this quirky challenge — think differently and critically. Consider an example: If triangle ABC is isosceles, what is the length of side BC? 1) The length of side AB is 4 2) The length of side AC is 4(sqrt2)
If you are thinking about content, you’re likely to first see that neither statement alone is sufficient (you’d need to know the lengths of at least two sides to make this determination). Secondly, you are likely to think about a particular isosceles triangle property: In an isosceles right triangle, the ratio of the sides is x : x : x(sqrt 2). And here you seem to have two of those sides – AB is 4, AC is the longer side, and so BC should also be 4. Right?
Not right – unless we know that the angle A is right! This triangle could also have sides of 4, 4sqrt2, and 4sqrt 2, and have all acute angles. The trap here is that the GMAT knows that you are studying particular triangle rules: 30-60-90s, 45-45-90s, 3-4-5s, 5-12-13s, etc. The authors of these questions want to tempt you, using the fact that you want to showcase the special rules that you’ve learned and prove to business schools that you’ve studied hard and have the capacity to accumulate knowledge.
But that’s not the whole game – knowledge is just one part of the GMAT, which also tests critical thinking skills, efficient processing of information, and other higher-order thought processes. So in order to succeed on harder questions, you have to embrace and accept that challenge — you have to think critically not just about “what do I know” but also “what DON’T I know.”
The GMAT is designed to stretch your mind and determine how flexibly and critically you think. As you study, don’t get frustrated by these mistakes, but instead accept the challenge to change the way you think to approach this test. Do so and you dramatically increase your chances of posting a high score. | 
