Is x > y

Expert replies

kamalakarthi: Senior | Next Rank: 100 Posts; Posts: 80; Joined: Mon Jan 31, 2011 10:08 pmFollowed by: 2 members

by kamalakarthi » Thu Jul 31, 2014 3:46 pm

Is x > y?

(1) x - y > 3

(2) x + y > 3

I am able to understand statement 1 is sufficient but not able to understand why statement 2 is not sufficient...

I can understand from statement 1 that x > 3+y so x must greater than y
but if I use x > 3-y ,I am thinking that it is still greater than x...Can u help me understand why this is not correct...

Can you please help.

Like this post

Source: Beat The GMAT — Data Sufficiency | Thu Jul 31, 2014 3:46 pm

GMAT/MBA Expert

Brent@GMATPrepNow: GMAT Instructor; Posts: 16207; Joined: Mon Dec 08, 2008 6:26 pmFollowed by: 1268 members; Location: Vancouver, BC; Thanked: 5254 times; GMAT Score:770

by Brent@GMATPrepNow » Thu Jul 31, 2014 4:22 pm

kamalakarthi wrote:Is x > y?

(1) x - y > 3
(2) x + y > 3

Target question: Is x > y?

Statement 1: x - y > 3
Add y to both sides to get: x > y + 3
Important: We also know that y + 3 > y
So, we can combine both inequalities to get: x > y + 3 > y
Here, we can clearly see that x > y
Since we can answer the target question with certainty, statement 1 is SUFFICIENT

Statement 2: x + y > 3
There are several values of x and y that satisfy this condition. Here are two:
Case a: x = 5 and y = 2, in which case x + y > 3. In this case, x > y
Case b: x = 2 and y = 5, in which case x + y > 3. In this case, x < y
Since we cannot answer the target question with certainty, statement 2 is NOT SUFFICIENT

Answer = A

Cheers,
Brent

Brent Hanneson - Creator of GMATPrepNow.com

Like this post

sapuna: Senior | Next Rank: 100 Posts; Posts: 67; Joined: Thu Jul 17, 2014 11:04 amFollowed by: 2 members; Thanked: 3 times

by sapuna » Fri Aug 01, 2014 12:49 am

kamalakarthi wrote:Is x > y?

(1) x - y > 3

(2) x + y > 3

I am able to understand statement 1 is sufficient but not able to understand why statement 2 is not sufficient...

I can understand from statement 1 that x > 3+y so x must greater than y
but if I use x > 3-y ,I am thinking that it is still greater than x...Can u help me understand why this is not correct...

Can you please help.

Statement 1 will always be sufficient because we get x > y + 3. Regardless of the values of x and y (whether they are both positive , both negative, or x is positive and y is negative) x will always be > y because of the given inequality

Using statement 2 we get x > 3 - y. Not the same case as statement 1.

plug in some values if you can`t guess ti right away. x = 5 y =1 = > x > y
However, there are some different options. x = 1 y = 3 x > 3- y but y > x so statement 2 is not sufficient

Like this post

GMATinsight: Legendary Member; Posts: 1100; Joined: Sat May 10, 2014 11:34 pmFollowed by: 24 members; Location: New Delhi, India; Thanked: 205 times

by GMATinsight » Fri Aug 01, 2014 9:14 am

kamalakarthi wrote:Is x > y?

(1) x - y > 3

(2) x + y > 3

I am able to understand statement 1 is sufficient but not able to understand why statement 2 is not sufficient...

I can understand from statement 1 that x > 3+y so x must greater than y
but if I use x > 3-y ,I am thinking that it is still greater than x...Can u help me understand why this is not correct...

Can you please help.

Statement 2)x + y > 3

@x=1, y=3 : 1+3 > 3 and x < y
@x=3, y=1 : 3+1 > 3 and x > y
INSUFFICIENT

I hope this makes it clearer using Numbers

"GMATinsight"Bhoopendra Singh & Sushma Jha
Most Comprehensive and Affordable Video Course 2000+ CONCEPT Videos and Video Solutions
Whatsapp/Mobile: +91-9999687183 l [email protected]
Contact for One-on-One FREE ONLINE DEMO Class Call/e-mail
Most Efficient and affordable One-On-One Private tutoring fee - US$40-50 per hour

Like this post

Post new topic Post Reply

• Page 1 of 1

GMAT Course Reviews

560 reviews

1168 reviews

431 reviews

359 reviews

147 reviews

5/5

5 Star (560 Reviews)

"Target Test Prep is the closest to the official version of the GMAT exam, about 99% accuracy in terms of the quality and quantity of information. The course has excellently created singular sets of focused lessons and tests for every possible topic that one could come across in the official GMAT exam."

"The TTP course maximizes the efficiency of the time you spend studying. It will take time and effort but I could almost guarantee that if you complete the course exactly as it is laid out you will get an amazing score. They also have a very responsive team willing to help with any questions you might have."

"TTP has two things that I think no other test prep company offers: A teaching approach that reinforces understanding and an attitude that will give you the mental preparedness needed to succeed on the test. TTP gives you a deep understanding of the concept you need to know while teaching you how to think."

Write a Review