For me, one of the most exciting parts of Kaplan’s new GMAT revision for 2010 is its emphasis on Identifying the Task in Quantitative Problem Solving questions.  Often, Problem Solving questions give a test-taker a large amount of information–sometimes as much as five or six equations’ worth–and when the pressure is on and the clock is ticking, it can be tough to get this information organized enough to answer the question, not to mention the amount of time that can be lost in doing so.

One of the most efficient ways of zeroing in on the answer in complicated questions is to use what I call a “master equation.”  For example, if I see the phrase “average (arithmetic mean)” in the first line of a Quantitative question, I immediately shoot down to my noteboard and jot down the average formula: “Average = (Sum of terms)/(Number of terms),” or my preferred abbreviated version, “Avg = sum/#.”

The logic behind it?  Well, if a question stem is mentioning an average in its first few words, I’m going to have to use the formula at some point, whether the question ends up needing the value of the average, the sum of the terms, or some other relationship.  With the formula already written before I even finish reading the question stem, I save myself the time and effort of recalling it later on, when I’ll be more concerned about the tricky, GMAT-ty aspects of solving the problem.  If I’m lucky–say, for example, the question from above gives us an average and a number of terms, and asks for the sum of the terms–I can even plug values directly into my master equation, solve algebraically, and get to the answer that much faster.  This can be very effective even complicated algebra questions where you’re not sure what the first step is–at least you can use the equations you know to do SOMETHING, instead of sitting there without knowing what to do.  When you keep your eventual goal (your “master equation”) prominent and proud at the very top of your scratch work, you’ll find it very difficult to lose focus!

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