It is currently 20 Oct 2017, 13:27

### 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

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

# Events & Promotions

###### Events & Promotions in June
Open Detailed Calendar

# If n = p/q where p and q are non zero integers, is n an

Author Message
Retired Moderator
Joined: 18 Jul 2008
Posts: 960

Kudos [?]: 295 [0], given: 5

If n = p/q where p and q are non zero integers, is n an [#permalink]

### Show Tags

30 Nov 2008, 21:45
00:00

Difficulty:

(N/A)

Question Stats:

100% (00:00) correct 0% (00:00) wrong based on 1 sessions

### HideShow timer Statistics

This topic is locked. If you want to discuss this question please re-post it in the respective forum.

If n = p/q where p and q are non zero integers, is n an integer?

(1) n^2 is an integer

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

Kudos [?]: 295 [0], given: 5

Director
Joined: 14 Aug 2007
Posts: 726

Kudos [?]: 212 [0], given: 0

Re: DS: Is n an integer? [#permalink]

### Show Tags

30 Nov 2008, 22:51
If n = p/q where p and q are non zero integers, is n an integer?

(1) n^2 is an integer

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

Tricky Q!

1) n^2 = Integer, n = sqrt(Integer)

Square roots of integers that are not perfect squares are always irrational numbers i.e Square roots can either be integers or irrational numbers (i.e later meaning that they can not be expressed as p/q)

since n can be expressed as p/q, it must be an integer. and thus 1 is sufficient.

2) is straightforward n+1/2 = integer i.e n = 2*integer - 1 and thus n should be integer.

D for me.

Kudos [?]: 212 [0], given: 0

Manager
Joined: 28 Apr 2008
Posts: 110

Kudos [?]: 12 [0], given: 0

Re: DS: Is n an integer? [#permalink]

### Show Tags

01 Dec 2008, 04:05
D

1-->(p/q)^2= n^2, and n^2 is an integer

we know that p and q are non zero integers.

we also know that any non integer root of an integer is a irrational number, i.e., a number which cannot be expressed as a fraction m/n, where m and n are integers.

thus, p/q, which is the root of n^2, must be an integer becaus it can be expressed as a fraction p/q, where p and q are integers.

==>1 is suff

2--> suff

D

Kudos [?]: 12 [0], given: 0

Re: DS: Is n an integer?   [#permalink] 01 Dec 2008, 04:05
Display posts from previous: Sort by