BREAKING: Target Test Prep releases Brand New 2026 On Demand GMAT prep course

Redeem

GMATPrep - Sum of Distances

This topic has expert replies
Post new topic Post Reply
Previous Topic Next Topic
Source: — Problem Solving |
Master | Next Rank: 500 Posts
Posts: 119
Joined: Sun Nov 30, 2008 2:47 am
Thanked: 11 times

by Zipper » Sun Dec 07, 2008 8:58 am
1. Doesn't mean anything, a and b can both be positive for instance and a can be negative b can be positive.

2. If a and b were on the same side (both positive or both negative) the module of their sum will equal the distance from 0 to a + the distance from 0 to b. However, it is said that the distance is greater so this simply means a and b are not on the same side so 0 is certainly between them.

therefore, B
Top
User avatar
GMAT Instructor
Posts: 3225
Joined: Tue Jan 08, 2008 2:40 pm
Location: Toronto
Thanked: 1710 times
Followed by:614 members
GMAT Score:800

by Stuart@KaplanGMAT » Sun Dec 07, 2008 9:12 am
We can also solve this using absolute values.

The distance between a number and 0 is the absolute value of that number.

Let's start by rephrasing the question (often a great first step in DS):

Q: If neither a nor b is 0, do a and b have different signs?

Then we rephrase the statements as:

(1) |a| > |b|

(2) |a| + |b| > |a + b|

(1) says nothing about the signs of a and b: insufficient.

(2) if a and b have the same sign, then |a| + |b| = |a + b|. The only way that (2) can be true is if a and b have different signs: sufficient.

(2) is sufficient but (1) is not: choose (B).
Image

Stuart Kovinsky | Kaplan GMAT Faculty | Toronto

Kaplan Exclusive: The Official Test Day Experience | Ready to Take a Free Practice Test? | Kaplan/Beat the GMAT Member Discount
BTG100 for $100 off a full course
Top
Post new topic Post Reply
• Page 1 of 1