GMAT Question of the Day – Problem Solving – Exponents

Which of the following is equal to (.9997)^2

A. .99940004

B. .99940009

C. .99949991

D. .99960049

E. .99969991

[spoiler]B.[/spoiler]

GMAT Question of the Day Solution

Here’s a question of the day with some seemingly tough calculations but with any GMAT question you should consider whether there’s another way to proceed. Here you might think about your options with exponents. You also might consider changing the shape of the number to something that is easier to deal with. In this case you can see that .9997 is very close to 1. So go and re-arrange the number to 1 – .003 which can be further compacted to 1 – 3*10^-3. Now you have the (x-y)^2 format or x^2 – 2xy + y^2 (know your special quadratics!). Simplify and you’ll get to the answer. Having some trouble simplifying this expression? Review your exponent rules. This stuff should be relatively straight forward.