Official Guide Explanation:
Data Sufficiency #65

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: 65
Page: 157
Difficulty: 3 (Very Easy)
Category 1: Geometry > Triangles > Length of sides

Explanation: Statement (1) is insufficient: if you only know the length of one side of a triangle, you must know the ratio of the sides or the measures of the angles to determine the length of another sides. Statement (2) is insufficient for the same reason.

Taken together, the statements are still insufficient. Knowing the lengths of two sides of a triangle gives a range of possible values for the third side, but without any other information about the triangle, they are not enough to find an exact length. Choice (E) 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.