Official Guide Explanation:
Data Sufficiency #20

Background

This is just one of hundreds of free explanations I've created to the quantitative questions in The Official Guide for GMAT Quantitative Review (2nd 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: 20
Page: 154
Difficulty: 4 (Moderately Easy)
Category 1: Arithmetic > Properties of Integers > Other

Explanation: Statement (1) is insufficient: it gives no indication of the relationship between y and the other variables. Statement (2) is also insufficient: in order for integers to be consecutive, they must be separated by exactly 1, and there's no information here about how far apart the integers are.

Taken together, the statements are sufficient. If z - x = 2, then z is 2 greater than x. If that is the case and x < y < z, there's only one integer between x and z, and that's y. Therefore, x, y, and z are consecutive integers. Choice (C) is correct.

Click here for the full list of GMAT Quant Review explanations.

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.