December 13, 2018 December 13, 2018 08:00 AM PST 09:00 AM PST What people who reach the high 700's do differently? We're going to share insights, tips and strategies from data we collected on over 50,000 students who used examPAL. December 14, 2018 December 14, 2018 09:00 AM PST 10:00 AM PST 10 Questions will be posted on the forum and we will post a reply in this Topic with a link to each question. There are prizes for the winners.
Author 
Message 
TAGS:

Hide Tags

Senior Manager
Joined: 24 Feb 2008
Posts: 347
Schools: UCSD ($) , UCLA, USC ($), Stanford

If x and y are both integers greater than 1, is x a multiple
[#permalink]
Show Tags
04 May 2008, 18:26
Question Stats:
62% (01:33) correct 38% (01:50) wrong based on 258 sessions
HideShow timer Statistics
If x and y are both integers greater than 1, is x a multiple of y? (1) 3y^2 + 7y = x (2) x^2 x is a multiple of y
Official Answer and Stats are available only to registered users. Register/ Login.
_________________
Chinese Democracy is misunderstood...at your nearest BestBuy.
Best AWA guide here: http://gmatclub.com/forum/howtoget60awamyguide64327.html



SVP
Joined: 04 May 2006
Posts: 1666
Schools: CBS, Kellogg

Re: DS: x multiple of y?
[#permalink]
Show Tags
04 May 2008, 19:35
chineseburned wrote: If x and y are both integers greater than 1, is x a multiple of y?
(1) 3y^2 + 7y = x (2) x^2 x is a multiple of y Hi, it is long time to see you! 1 suff. no discustion 2. x(x1) is multiple of y. So x may or may not is multiple of y. a. x=5, y = 2 5*6 is multiple of 2, but x=5 is not multiple of 2 b. x=6 6*7 is multiple of 2, and x=6 is multiple of 2
_________________
GMAT Club Premium Membership  big benefits and savings



VP
Joined: 10 Jun 2007
Posts: 1357

Re: DS: x multiple of y?
[#permalink]
Show Tags
04 May 2008, 19:55
chineseburned wrote: If x and y are both integers greater than 1, is x a multiple of y?
(1) 3y^2 + 7y = x (2) x^2 x is a multiple of y A. Given: x > 1 y > 1 n, x, y = integer Asking: Is x = ny? (1) x = y*(3y + 7) Because y is integer, (3y + 7) must be integer; therefore, x must equal integer * y SUFFICIENT (2) x^2  x = ny Plug in numbers to satisfy above condition... Say x=3, n=1, then y=6. In this case, x is not a multiple of y. Say x=6, n=15, then y=2. In this case, x is a multiple of y. The solution actually depends on what n is, and the only condition we have is n is integer. Therefore, it is INSUFFICIENT



SVP
Joined: 29 Aug 2007
Posts: 2366

Re: DS: x multiple of y?
[#permalink]
Show Tags
04 May 2008, 20:29
chineseburned wrote: If x and y are both integers greater than 1, is x a multiple of y?
(1) 3y^2 + 7y = x (2) x^2 x is a multiple of y (1) 3y^2 + 7y = x y (3y + 7) = x so x must be a multiple, (3y+7) times, of y. suff... (2) x^2 x is a multiple of y x^2  x = yk where k is an integer. x (x1) = yk from this we do not know whether x  1 or x is equal to k. so nsf.... A.
_________________
Verbal: http://gmatclub.com/forum/newtotheverbalforumpleasereadthisfirst77546.html Math: http://gmatclub.com/forum/newtothemathforumpleasereadthisfirst77764.html Gmat: http://gmatclub.com/forum/everythingyouneedtoprepareforthegmatrevised77983.html
GT



Intern
Joined: 08 Apr 2008
Posts: 41

Re: DS: x multiple of y?
[#permalink]
Show Tags
24 Jun 2008, 17:02
GMAT TIGER wrote: (2) x^2 x is a multiple of y x^2  x = yk where k is an integer. x (x1) = yk from this we do not know whether x  1 or x is equal to k. so nsf....
What is the reasoning behind multiplying y by another variable in Statement 2 (in this case k)?



Director
Joined: 14 Aug 2007
Posts: 676

Re: DS: x multiple of y?
[#permalink]
Show Tags
24 Jun 2008, 22:26
AlinderPatel wrote: GMAT TIGER wrote: (2) x^2 x is a multiple of y x^2  x = yk where k is an integer. x (x1) = yk from this we do not know whether x  1 or x is equal to k. so nsf....
What is the reasoning behind multiplying y by another variable in Statement 2 (in this case k)? 2)x^2 x is a multiple of y let K be the multiple. then x^2x = K . y Hope this helps



Intern
Joined: 10 Jun 2010
Posts: 2

Re: DS: x multiple of y?
[#permalink]
Show Tags
10 Jun 2010, 06:41
so if we have
y^2y = X
Then we could say with certitude that X is a multiple of Y?



Intern
Joined: 02 May 2010
Posts: 48
Schools: IU, UT Dallas, Univ of Georgia, Univ of Arkansas, Miami University
WE 1: 5.5 Yrs IT

Re: DS: x multiple of y?
[#permalink]
Show Tags
10 Jun 2010, 06:54
Yes. If it was given that y^2y = x, then x is certainly a multiple of y.
y^2y = x y(y1) = x y*k = x



Intern
Joined: 16 Jul 2010
Posts: 18

Re: DS: x multiple of y?
[#permalink]
Show Tags
17 Jul 2010, 06:52
So from x(x1)=yk, can we not derive: x=y*k/(x1)=yk? In which case the answer is C, not A.
_________________
If you find my posts useful, please award me some Kudos!



Math Expert
Joined: 02 Sep 2009
Posts: 51184

Re: DS: x multiple of y?
[#permalink]
Show Tags
17 Jul 2010, 07:12
dauntingmcgee wrote: So from x(x1)=yk, can we not derive:
x=y*k/(x1)=yk?
In which case the answer is C, not A. We don't know whether \(\frac{k}{x1}\) is an integer, hence we can not write \(x=yn\) (where n is an integer) from \(x(x1)=yk\). If x and y are integers great than 1, is x a multiple of y?Is \(x=ny\), where \(n=integer\geq{1}\)? (1) \(3y^2+7y=x\) > \(y(3y+7)=x\) > as \(3y+7=integer\), then \(y*integer=x\) > \(x\) is a multiple of \(y\). Sufficient. (2) \(x^2x\) is a multiple of \(y\) > \(x^2x=my\) > \(x(x1)=my\) > \(x\) can be multiple of \(y\) (\(x=2\) and \(y=2\)) OR \(x1\) can be multiple of \(y\) (\(x=3\) and \(y=2\)) or their product can be multiple of \(y\) (\(x=3\) and \(y=6\)). Not sufficient. Answer: A. Hope it helps.
_________________
New to the Math Forum? Please read this: Ultimate GMAT Quantitative Megathread  All You Need for Quant  PLEASE READ AND FOLLOW: 12 Rules for Posting!!! Resources: GMAT Math Book  Triangles  Polygons  Coordinate Geometry  Factorials  Circles  Number Theory  Remainders; 8. Overlapping Sets  PDF of Math Book; 10. Remainders  GMAT Prep Software Analysis  SEVEN SAMURAI OF 2012 (BEST DISCUSSIONS)  Tricky questions from previous years.
Collection of Questions: PS: 1. Tough and Tricky questions; 2. Hard questions; 3. Hard questions part 2; 4. Standard deviation; 5. Tough Problem Solving Questions With Solutions; 6. Probability and Combinations Questions With Solutions; 7 Tough and tricky exponents and roots questions; 8 12 Easy Pieces (or not?); 9 Bakers' Dozen; 10 Algebra set. ,11 Mixed Questions, 12 Fresh Meat DS: 1. DS tough questions; 2. DS tough questions part 2; 3. DS tough questions part 3; 4. DS Standard deviation; 5. Inequalities; 6. 700+ GMAT Data Sufficiency Questions With Explanations; 7 Tough and tricky exponents and roots questions; 8 The Discreet Charm of the DS; 9 Devil's Dozen!!!; 10 Number Properties set., 11 New DS set.
What are GMAT Club Tests? Extrahard Quant Tests with Brilliant Analytics



Intern
Joined: 16 Jul 2010
Posts: 18

Re: DS: x multiple of y?
[#permalink]
Show Tags
17 Jul 2010, 09:46
Yes, that is great. Thank you. Guess I'm a little rustier than I thought.
_________________
If you find my posts useful, please award me some Kudos!



Manager
Joined: 11 May 2018
Posts: 92
Location: India

Re: If x and y are both integers greater than 1, is x a multiple
[#permalink]
Show Tags
18 Aug 2018, 23:29
could someone please explain me the option 2 by plugging numbers. I have not understood the above solutions. Thank you.
_________________
If you want to Thank me Give me a KUDOS "I’ve spent months preparing for the day I’d face you. I’ve come a long way, GMAT" SonGoku



Manager
Joined: 06 Nov 2016
Posts: 62
Location: Viet Nam
Concentration: Strategy, International Business
GPA: 3.54

Re: If x and y are both integers greater than 1, is x a multiple
[#permalink]
Show Tags
19 Aug 2018, 08:12
SonGoku wrote: could someone please explain me the option 2 by plugging numbers. I have not understood the above solutions. Thank you. (2) \(x^2−x\) is a multiple of y Number plugging approach: Let \(y=2\) If \(x=3\) > \(x^2−x\) = \(3^23 = 6\) > \(x^2−x\) is a multiple of y BUT x is not a multiple of y > NO If \(x=4\) > \(x^2−x\) = \(4^24 = 12\) > \(x^2−x\) is a multiple of y and x is a multiple of y > YES > Insufficient. Hope it's clear.
_________________
（＾人＾）
GMATCLUB Search for tags
GMAC © Official Guides  The Master Directory + Links
Question Directory by Topic & Difficulty Problem Solving  Data Sufficiency  Sentence Correction  Critical Reasoning  Reading Comprehension
ONLINE FREE (FULL LENGTH) GMAT CAT (PRACTICE TESTS) LINK COLLECTION




Re: If x and y are both integers greater than 1, is x a multiple &nbs
[#permalink]
19 Aug 2018, 08:12






