Official Guide Explanation:
Problem Solving #114




This is just one of hundreds of free explanations I've created to the quantitative questions in The Official Guide for GMAT Review (12th ed.). Click the links on the question number, difficulty level, and categories to find explanations for other problems.

These are the same explanations that are featured in my "Guides to the Official Guide" PDF booklets. However, because of the limitations of HTML and cross-browser compatibility, some mathematical concepts, such as fractions and roots, do not display as clearly online.

Click here for an example of the PDF booklets. Click here to purchase a PDF copy.


Solution and Metadata

Question: 114
Page: 168
Difficulty: 5 (Moderate)
Category 1: Arithmetic > Powers and Roots of Numbers > Powers
Category 2: Arithmetic > Decimals >
Category 3: Arithmetic > Real Numbers >

Explanation: While it wouldn't take long to calculate a2 and a3 for a= - 0.3, it's not necessary. There are a few facts you do need to recognize, though. First, if a is negative, a2 is positive and a3 is negative. Second, since a is a negative decimal, a3 is greater than a; when decimals are multiplied by themselves, they get closer to zero. So, taking all that information together, a < a3 < a2, choice (B).

Click here for the full list of GMAT OG12 explanations.


You should follow me on Twitter. While you're at it, take a moment to subscribe to GMAT Hacks via RSS or Email.

Total GMAT Math

The comprehensive guide to the GMAT Quant section. It's "far and away the best study material available," including over 300 realistic practice questions and more than 500 exercises!
Click to read more.