It is currently 17 Jan 2018, 06:52

Close

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.

Close

Request Expert Reply

Confirm Cancel

Events & Promotions

Events & Promotions in June
Open Detailed Calendar

If z is an integer, is y an integer?

  new topic post reply Question banks Downloads My Bookmarks Reviews Important topics  
Author Message
TAGS:

Hide Tags

Expert Post
Math Expert
User avatar
D
Joined: 02 Aug 2009
Posts: 5518

Kudos [?]: 6410 [0], given: 122

If z is an integer, is y an integer? [#permalink]

Show Tags

New post 29 Nov 2017, 18:01
00:00
A
B
C
D
E

Difficulty:

  55% (hard)

Question Stats:

59% (00:49) correct 41% (00:50) wrong based on 37 sessions

HideShow timer Statistics

If z is an integer, is y an integer?

(1) \(y^2-z=0\)
(2) \(y\neq{1}\)
[Reveal] Spoiler: OA

_________________

Absolute modulus :http://gmatclub.com/forum/absolute-modulus-a-better-understanding-210849.html#p1622372
Combination of similar and dissimilar things : http://gmatclub.com/forum/topic215915.html


BANGALORE/-


Last edited by Bunuel on 29 Nov 2017, 19:40, edited 1 time in total.
Renamed the topic, edited the question

Kudos [?]: 6410 [0], given: 122

Senior Manager
Senior Manager
avatar
D
Joined: 27 May 2014
Posts: 363

Kudos [?]: 232 [0], given: 84

GMAT 1: 730 Q49 V41
GMAT ToolKit User Premium Member
Re: If z is an integer, is y an integer? [#permalink]

Show Tags

New post 29 Nov 2017, 18:12
chetan2u wrote:
If z is an integer, is y an integer?
(1) \(y^2-z=0\)
(2) \(y\neq{1}\)


(1)
Suppose z = 3;
Then y = ±√3 = Not integer

again, suppose z= 4;
Then y = √4 = ±2 = Integer
Hence, Insuff.

(2) y≠1; Consider y = ±√3 or y = ±2
conditions in (1) still hold true. Insuff.

(1) & (2) together,
conditions in (1) still hold true. Insuff.
Ans: E.

Kudos [?]: 232 [0], given: 84

Manager
Manager
avatar
B
Joined: 31 Jul 2017
Posts: 142

Kudos [?]: 22 [0], given: 491

Location: Malaysia
WE: Consulting (Energy and Utilities)
Re: If z is an integer, is y an integer? [#permalink]

Show Tags

New post 29 Nov 2017, 18:21
chetan2u wrote:
If z is an integer, is y an integer?
(1) \(y^2-z=0\)
(2) \(y\neq{1}\)


Hi chetan2u,

From Stmnt 1: \(z\)= \(y^2\), y can be \(\sqrt{3}\), \(\sqrt{5}\)
From Stmnt 2: y # 1.. Insufficient

Combined.. Not Sufficient.. So E.

Kudos [?]: 22 [0], given: 491

DS Forum Moderator
avatar
S
Joined: 21 Aug 2013
Posts: 655

Kudos [?]: 210 [0], given: 298

Location: India
Premium Member CAT Tests
Re: If z is an integer, is y an integer? [#permalink]

Show Tags

New post 29 Nov 2017, 21:29
(1) y^2 - z = 0 or y^2 = z
This tells us that z is a non negative integer, but we cannot say anything about y.
Here y will be an integer if z is a perfect square, else not. Insufficient.

(2) y is not equal to 1. This doesnt tell us whether y is an integer or not. Insufficient.

Combining the two statements, y=√z and y is not equal to 1. Still there are multiple possibilities. We can have z=9, then y can take two values: 3 or -3 (integer values). But if z =8, then y = √8 or -√8 (non integer values). So insufficient.

Hence E answer

Kudos [?]: 210 [0], given: 298

Re: If z is an integer, is y an integer?   [#permalink] 29 Nov 2017, 21:29
Display posts from previous: Sort by

If z is an integer, is y an integer?

  new topic post reply Question banks Downloads My Bookmarks Reviews Important topics  


GMAT Club MBA Forum Home| About| Terms and Conditions| GMAT Club Rules| Contact| Sitemap

Powered by phpBB © phpBB Group | Emoji artwork provided by EmojiOne

Kindly note that the GMAT® test is a registered trademark of the Graduate Management Admission Council®, and this site has neither been reviewed nor endorsed by GMAC®.