Data Sufficiency

Hi fambrini,

I'm going to give you a few hints so that you can retry this question on your own:

[spoiler]Notice how Fact 1 does not tell you anything about variable "A" and Fact 2 doesn't tell you anything about variable "C"... it's pretty obvious that each of those Facts is insufficient on its own. When combining Facts, try TESTing VALUES. What values would be easy to TEST? Hint: choose the same value for all 3 variables. Once you've done that, what else could you TEST (and what would the result be?)? After TESTing 3 different sets of numbers, what do you notice about the results? Are they consistent or not?[/spoiler]

GMAT assassins aren't born, they're made,
Rich

fambrini wrote:If a ≠ 0, b ≠ 0, c ≠ 0, is a(b + c) > 0?

1) |b - c| = |b| - |c|

2) |a + b| = |a| + |b|

OA: C

We need to determine whether a(b + c) > 0.

Statement One Alone:

|b - c| = |b| - |c|

In analyzing statement one, we can use the following rule: When we are given the absolute value equation |b - c| = |b| - |c|, we know that

1) The values of b and c have the same sign.

2) |b| > |c|

However, because we do not know the sign of the value of a, statement one is not enough information to answer the question. We can eliminate answer choices A and D.

Statement Two Alone:

|a + b| = |a| + |b|

In analyzing statement two we can use the following rule:when we are given the absolute value equation |a + b| = |a| + |b|, we know that

1) The values of a and b have the same sign.

However, because we do not know the sign of the value of c, statement two is not enough information to answer the question. We can eliminate answer choice B.

Statements One and Two Together:

Using the information from statements one and two, we know the following:

The values of b and c have the same sign and the values of a and b have the same sign. Thus, we know that the values of a, b, and c all have the same sign. With that information we can determine that a(b + c) > 0.

Answer: C