LBS is Calling R1 Admits - Join Chat Room to Catch the Latest Action
GMAT Club Daily Prep
Thank you for using the timer - this advanced tool can estimate your performance and suggest more practice questions. We have subscribed you to Daily Prep Questions via email.
Customized for You
we will pick new questions that match your level based on your Timer History
Track Your Progress
every week, we’ll send you an estimated GMAT score based on your performance
Practice Pays
we will pick new questions that match your level based on your Timer History
Not interested in getting valuable practice questions and articles delivered to your email? No problem, unsubscribe here.
Thank you for using the timer!
We noticed you are actually not timing your practice. Click the START button first next time you use the timer.
There are many benefits to timing your practice, including:
Mark your calendars - All GMAT Club Tests are free and open November 22nd to celebrate Thanksgiving Day! Access will be available from 0:01 AM to 11:59 PM, Pacific Time (USA)
Re: Given x = y + z. Is x > y ? (1) y > 0 (2) z > 0
[#permalink]
Show Tags
15 Jun 2018, 09:43
1
Top Contributor
gmatbusters wrote:
Given x = y + z. Is x > y ?
1) y > 0 2) z > 0
Great question!
Given: Given x = y + z
Target question:Is x > y ? This is a good candidate for rephrasing the target question.
Aside: the video below has tips on rephrasing the target question
Take 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 0 Case 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 0 Since we cannot answer the REPHRASED target question with certainty, statement 1 is NOT SUFFICIENT
Statement 2: z > 0 It'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 > 0 PERFECT!! The answer to the REPHRASED target question is YES, x - y IS greater than 0 Since we can answer the REPHRASED target question with certainty, statement 2 is SUFFICIENT
close
50% (00:47) correct 
