(This is one of a series of GMAT tips that we offer on our blog.)
Variability Equals Flexibility
Often times, examinees become confused when quantitative problems use large or seemingly-abstract numbers, such as 12!, 2^17, or multi-item expressions, such as 3^(x-2). The more convoluted a value might seem, the easier it is to grow frustrated, lose focus, or simply consider the problem to be too difficult.
Naturally, those reactions to such numbers are precisely the reason why the GMAT includes them – distracted, intimidated, and defeated examinees tend to miss questions and earn lower scores, which in turn allows the exam to maintain its difficulty level.
Keep in mind, though, that the exam will not typically require extensive calculations or the processing of large numbers. To avoid becoming discouraged simply because of the size and scope of the values or expressions you face, consider creating a variable as a placeholder for that term so that you can perform the calculations that surround it without the distraction of the intimidating term. Consider:
12! + 12!/2 +3(12!)/2
This item would look to be quite intimidating to calculate, and may lead to debate over whether any of the individual terms could be combined (does 12!/2 = 6! … it does not, but the thought may present itself to a flustered test-taker). However, if you were to replace 12! with x, the calculation becomes much clearer:
x + x/2 + 3x/2 = x + 4x/2 = x + 2x = 3x
Accordingly, the value of the above expression is 3(12!), which should match much closer with the format of the correct answer choice, or provide an easier basis for calculation with the rest of the problem.
Please note that this variable substitution strategy would also work for verbal questions, as well – should a technical term like “protoplanetary” give you trouble when reading, you may want to simply abbreviate it mentally and call it “P”. “The P theory states that…” is a lot easier to manage than “The protoplanetary theory states that…”, and allows you to focus on what is important – that a particular theory is being defined in that statement.