### Bookshelf

Total GMAT MathJeff's complete Quant guide, on sale now! |

Total GMAT VerbalEverything you need to ace GMAT Verbal! |

New: GMAT 111Improve every aspect of your GMAT prep! |

**1,800 Practice Math Questions**

GMAT Official Guide

OG Math | OG Verbal

Guides To the Official Guide

Free: OG12 explanations!

**GMAT Question of the Day**

Beginner's Guide to the GMAT

GMAT Hacks Affiliate Program

### Categories

- General Study Tips
- Goals and Planning
- CAT Strategy
- The Mental Game
- GMAT Math Strategy
- GMAT Math Topics
- Mental Math
- Data Sufficiency
- Critical Reasoning
- Reading Comprehension
- Sentence Correction
- Analytical Writing Assessment
- Business School Admissions
- GMAT Prep Resources
- Practice Questions
- Total GMAT Math
- Total GMAT Verbal

## Official Guide Explanation:

Data Sufficiency #D39

**Background**

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****: D39**

Page: 25

Difficulty: **6** (Moderately Difficult)

Category 1: Geometry > Coordinate Geometry > Slope

Category 2: Geometry > Coordinate Geometry > Other

**Explanation:** Knowing that a line passes through the point (-5,r) isn't very helpful--almost every point has a point somewhere with an x - coordinate of -5. Before attacking the statements, think about lines with a negative slopes, and what would be required for such a line to have a positive x - intercept. A line with a negative slope moves down and to the right (or up and to the left, depending on how you think about it). If such a line passes through the x - axis when x is positive, one way to think about it is that it starts in the upper left quadrant, moves into the upper right quadrant after passing through the y - axis, then passes into the lower right quadrant after passing through the x - axis.

Statement (1) is insufficient. Knowing the slope tells us the "tilt" or angle of the line, but nothing about the intercepts of the line.

Statement (2) is also insufficient. In the scenario described above, r must be positive. (When the line is to the left of the origin, the y value must be positive.) However, it's possible that r is positive and the x - intercept is negative. If the point is, say, (-5, - 1) and the line moves sharply downward, the x - intercept will be negative.

Taken together, the statements are insufficient. I've already described the situation in which the answer would be "no"--if r = 1 and the slope is -5 (that is, it moves sharply downward), the x - intercept will be negative. However, if r is sufficiently great (say, r = 1000--there's no limit on how great r can be), even a line moving sharply downward will have positive x- and y - intercepts. Choice (E) is correct.

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! |