If n = p/q, where p and q are nonzero integers

This topic has expert replies
Master | Next Rank: 500 Posts
Posts: 366
Joined: Fri Jun 05, 2015 3:35 am
Thanked: 3 times
Followed by:2 members
If n = p/q, where p and q are nonzero integers, is n an integer?

1) n^2 is an integer.

2) (2n + 4) / 2 is an integer.

OA: D

User avatar
GMAT Instructor
Posts: 15539
Joined: Tue May 25, 2010 12:04 pm
Location: New York, NY
Thanked: 13060 times
Followed by:1906 members
GMAT Score:790

by GMATGuruNY » Mon Feb 12, 2018 4:21 am
NandishSS wrote:If n = p/q, where p and q are nonzero integers, is n an integer?

1) n^2 is an integer.

2) (2n + 4) / 2 is an integer.
Statement 1:
Either n is an integer or n is an irrational number such as √2.
An irrational number cannot be written as integer/integer.
Since n = p/q = integer/integer, n cannot be an irrational number such as √2.
Thus, n must be an integer, and the answer to the question stem is YES.
SUFFICIENT.

Statement 2:
(2n + 4)/2 = integer
n + 2 = integer
n = integer - 2 = integer - integer = integer.
Thus, the answer to the question stem is YES.
SUFFICIENT.

The correct answer is D.
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