If x and y are integers and xy = 4, what is the value of y?

Expert replies

gmattesttaker2: Legendary Member; Posts: 641; Joined: Tue Feb 14, 2012 3:52 pmFollowed by: 8 members; Thanked: 11 times

by gmattesttaker2 » Thu Feb 13, 2014 9:18 pm

Hello,

Can you please assist with this:

If x and y are integers and xy = 4, what is the value of y?
(1) x = y - 3
(2) x = 1

OA: B

However, I am getting D

xy = 4
=> 1.4 = 4
or 2.2 = 4
or 4.1 = 4

1) x = y - 3 => x + 3 = y

Hence, x = 1. So y = 4

Hence, suff.

2) x = 1

Suff.

Hence, D

Thanks,
Sri

Like this post

Source: Beat The GMAT — Data Sufficiency | Thu Feb 13, 2014 9:18 pm

GMATGuruNY: GMAT Instructor; Posts: 15539; Joined: Tue May 25, 2010 12:04 pmFollowed by: 1906 members; Location: New York, NY; Thanked: 13060 times; GMAT Score:790

by GMATGuruNY » Thu Feb 13, 2014 9:41 pm

gmattesttaker2 wrote:Hello,

Can you please assist with this:

If x and y are integers and xy = 4, what is the value of y?
(1) x = y - 3
(2) x = 1

Given that x and y are integers and that xy=4, the following cases are possible:
x=1, y=4
x=-1, y=-4
x=2, y=2
x=-2, y=-2
x=4, y=1
x=-4, y=-1.

Statement 1: x = y-3
In other words, x is 3 less than y.
Of the six cases listed above, two are such that x is 3 less than y:
x=1, y=4
x=-4, y=-1.
Since it's possible that y=4 or that y=-1, INSUFFICIENT.

Statement 2: x=1
Of the six cases listed above, only one includes x=1:
x=1, y=4.
Thus, y=4.
SUFFICIENT.

The correct answer is B.

Private tutor exclusively for the GMAT and GRE, with over 20 years of experience.
Followed here and elsewhere by over 1900 test-takers.
I have worked with students based in the US, Australia, Taiwan, China, Tajikistan, Kuwait, Saudi Arabia -- a long list of countries.
My students have been admitted to HBS, CBS, Tuck, Yale, Stern, Fuqua -- a long list of top programs.

As a tutor, I don't simply teach you how I would approach problems.
I unlock the best way for YOU to solve problems.

For more information, please email me (Mitch Hunt) at [email protected].
Student Review #1
Student Review #2
Student Review #3

Like this post

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 » Fri Feb 14, 2014 8:33 am

gmattesttaker2 wrote:Hello,

Can you please assist with this:

If x and y are integers and xy = 4, what is the value of y?
(1) x = y - 3
(2) x = 1

OA: B

However, I am getting D

xy = 4
=> 1.4 = 4
or 2.2 = 4
or 4.1 = 4

1) x = y - 3 => x + 3 = y

Hence, x = 1. So y = 4

Hence, suff.

2) x = 1

Suff.

Hence, D

Thanks,
Sri

Hey Sri,

I think you read the question as "If x and y are positive integers . . .," in which case the answer would, indeed, be D

Cheers,
Brent

Brent Hanneson - Creator of GMATPrepNow.com

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