GMATPrepNow wrote:

fiendex wrote:

If a, b, and c are integers, is a - b + c greater than a + b - c?

(1) b is negative

(2) c is positive

Target question: Is 2a – b + c > a – b – 2c?This is a great candidate for

rephrasing the target question.

Aside: We have a video with tips on rephrasing the target question (below)Take 2a – b + c > a – b – 2c

Add b to both sides to get: 2a + c > a – 2c

Add 2c to both sides to get: 2a + 3c > a

Subtract a from both sides to get: a + 3c > 0

REPHRASED target question: Is a + 3c > 0? Statement 1: a is positive.No information about c, so there's no way to determine whether

a + 3c > 0Alternatively, we can examine some conflicting cases that satisfy statement 1 (a is positive):

Case a: a = 1 and c = 1, in which case

a + 3c > 0Case b: a = 1 and c = -1, in which case

a + 3c < 0Since we cannot answer the

REPHRASED target question with certainty, statement 1 is NOT SUFFICIENT

Statement 2: c is positive.No information about c, so there's no way to determine whether

a + 3c > 0Alternatively, we can examine some conflicting cases that satisfy statement 2 (c is positive):

Case a: a = 1 and c = 1, in which case

a + 3c > 0Case b: a = -5 and c = 1, in which case

a + 3c < 0Since we cannot answer the

REPHRASED target question with certainty, statement 2 is NOT SUFFICIENT

Statements 1 and 2 combined Statement 1 tells us that a is positive

Statement 2 tells us that c is positive

If a and c are both positive, then it MUST BE THE CASE that

a + 3c > 0Since we can answer the

REPHRASED target question with certainty, the combined statements are SUFFICIENT

Answer = C

Hi, how is the question rephrase from "If a, b, and c are integers, is a - b + c greater than a + b - c?" to "2a – b + c > a – b – 2c"?

Thank you.