gmatbusters
Given x = y + z. Is x > y ?
1) y > 0
2) z > 0
Great question!
Given: Given x = y + zTarget question: Is x > y ? This is a good candidate for
rephrasing the target question.
Aside: the video below has tips on rephrasing the target questionTake
x > y, and subtract y from both sides to get:
x - y > 0 So, asking
Is x > y? is the SAME AS asking
Is x - y > 0? REPHRASED target question: Is x - y >? Statement 1: y > 0 There are several values of x, y and z that satisfy statement 1. Here are two:
Case a: x = 3, y = 2 and z = 1 (this satisfies the given condition that x = y + z. In this case, x - y = 3 - 2 = 1. So, the answer to the REPHRASED target question is
YES, x - y IS greater than 0Case b: x = 2, y = 3 and z = -1 (this satisfies the given condition that x = y + z. In this case, x - y = 2 - 3 = -1. So, the answer to the REPHRASED target question is
NO, x - y is NOT greater than 0Since we cannot answer the
REPHRASED target question with certainty, statement 1 is NOT SUFFICIENT
Statement 2: z > 0It's given that x = y + z
This means that x - y = z
Since statement 1 tells us that z > 0, then it is the case that
x - y > 0PERFECT!!
The answer to the REPHRASED target question is
YES, x - y IS greater than 0Since we can answer the
REPHRASED target question with certainty, statement 2 is SUFFICIENT
Answer: B
Cheers,
Brent
RELATED VIDEO