Find all School-related info fast with the new School-Specific MBA Forum
Learn more about the recent changes... close

It is currently 19 Jun 2013, 07:50
Customize  |  Hide

Search
Register
New posts
Unanswered

M06 #16

  Question banks Downloads My Bookmarks Reviews  
  Oldest Best Reply
Search for:
 
Print view
First unread post
Author Message
Senior Manager
Senior Manager
Joined: 08 Jun 2010
Posts: 400
Location: United States
Concentration: General Management, Finance
Schools: Wharton '15 (D), Darden '15 (D), Johnson '15 (S)
GMAT 1: 680 Q50 V32
Followers: 1

Kudos [?]: 38 [0], given: 13

GMAT Tests User
M06 #16 [#permalink] New post 04 Feb 2012, 01:17
00:00

Question Stats:

100% (00:00) correct 0% (00:00) wrong based on 1 sessions
If \frac{t}{u} = \frac{x}{y} and \frac{t}{y} = \frac{u}{x} and t , u , x , and y are non-zero integers, which of the following is true?

A. \frac{t}{u}=1
B. \frac{y}{x}=-1
C. t = u
D. t = \pm u
E. None of the above

A question to Bunuel or someone who actually wrote the test:

From the given equation we get ux=ty (1) and xt=uy (2)
subtracting 2 from 1 this we get x(u-t)= y (t-u) --> this gives us x=-y. This is option B.
So, why is option B wrong?
1 KUDOS received
GMAT Club team member
User avatar
Joined: 02 Sep 2009
Posts: 12116
Followers: 1879

Kudos [?]: 10121 [1] , given: 963

GMAT Tests User CAT Tests
Top Member of the Month
Re: M06 #16 [#permalink] New post 04 Feb 2012, 08:52
1
This post received
KUDOS
mourinhogmat1 wrote:
If \frac{t}{u} = \frac{x}{y} and \frac{t}{y} = \frac{u}{x} and t , u , x , and y are non-zero integers, which of the following is true?

A. \frac{t}{u}=1
B. \frac{y}{x}=-1
C. t = u
D. t = \pm u
E. None of the above

A question to Bunuel or someone who actually wrote the test:

From the given equation we get ux=ty (1) and xt=uy (2)
subtracting 2 from 1 this we get x(u-t)= y (t-u) --> this gives us x=-y. This is option B.
So, why is option B wrong?


Because you can not tell from x(u-t)=y(t-u) that x=-y is necessarily true:
x(u-t)=y(t-u) --> x(u-t)+y(u-t)=(x+y)(t-u) --> either x=-y or t=u.

Complete solution:
Given that: \frac{t}{u} = \frac{x}{y} and \frac{t}{y} = \frac{u}{x}.

So, \frac{t}{u} = \frac{x}{y} and \frac{t}{u} = \frac{y}{x} (from 2), which means that \frac{t}{u} and \frac{x}{y} equal to their reciprocals: \frac{t}{u}=\frac{u}{t} and \frac{x}{y}=\frac{y}{x} --> t^2=u^2 and t^2=u^2 --> |t|=|u| (or which is the same t = \pm u) and |x|=|y| (or which is the same x = \pm y).

Answer: D.

One more thing: notice that answer choices A and C are the same, since we can not have two correct answers than both are wrong (there are some types of questions for which more than one answer can be correct but this is not that type).

Hope it's clear.
_________________

NEW TO MATH FORUM? PLEASE READ THIS: ALL YOU NEED FOR QUANT!!!

PLEASE READ AND FOLLOW: 11 Rules for Posting!!!

RESOURCES: [GMAT MATH BOOK]; 1. Triangles; 2. Polygons; 3. Coordinate Geometry; 4. Factorials; 5. Circles; 6. Number Theory; 7. Remainders; 8. Overlapping Sets; 9. PDF of Math Book; 10. Remainders

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. NEW!!! ,11 Mixed Questions NEW!!!, 12 Fresh Meat NEW!!!

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. NEW!!!, 11 New DS set. NEW!!!


What are GMAT Club Tests?
25 extra-hard Quant Tests

Find out what's new at GMAT Club - latest features and updates

Intern
Intern
Joined: 19 Oct 2012
Posts: 8
Followers: 1

Kudos [?]: -20 [0], given: 0

Re: M06 #16 [#permalink] New post 26 Mar 2013, 00:06
This is confusing. I solved this question and immediately got A as the write answer. Thanks for pointing that A and C are the same. But how do we find that A or C is wrong even after getting this answer?
Intern
Intern
Joined: 29 Jul 2012
Posts: 21
GMAT 1: 660 Q47 V34
Followers: 0

Kudos [?]: 1 [0], given: 6

Re: M06 #16 [#permalink] New post 15 Apr 2013, 17:14
I'm stumped on this one too. Not clear at all.
GMAT Club team member
User avatar
Joined: 02 Sep 2009
Posts: 12116
Followers: 1879

Kudos [?]: 10121 [0], given: 963

GMAT Tests User CAT Tests
Top Member of the Month
Re: M06 #16 [#permalink] New post 16 Apr 2013, 02:46
youngkacha wrote:
I'm stumped on this one too. Not clear at all.


Can you please tell me which part(s) of the solution didn't you understand?
_________________

NEW TO MATH FORUM? PLEASE READ THIS: ALL YOU NEED FOR QUANT!!!

PLEASE READ AND FOLLOW: 11 Rules for Posting!!!

RESOURCES: [GMAT MATH BOOK]; 1. Triangles; 2. Polygons; 3. Coordinate Geometry; 4. Factorials; 5. Circles; 6. Number Theory; 7. Remainders; 8. Overlapping Sets; 9. PDF of Math Book; 10. Remainders

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. NEW!!! ,11 Mixed Questions NEW!!!, 12 Fresh Meat NEW!!!

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. NEW!!!, 11 New DS set. NEW!!!


What are GMAT Club Tests?
25 extra-hard Quant Tests

Find out what's new at GMAT Club - latest features and updates

Intern
Intern
Joined: 29 Jul 2012
Posts: 21
GMAT 1: 660 Q47 V34
Followers: 0

Kudos [?]: 1 [0], given: 6

Re: M06 #16 [#permalink] New post 16 Apr 2013, 20:32
Bunuel wrote:
youngkacha wrote:
I'm stumped on this one too. Not clear at all.


Can you please tell me which part(s) of the solution didn't you understand?


I'm lost when you take the absolute value of t and u, yet u is +/- and t isn't.

Why is t = +/- u instead of being +/- t = +/- u?
Senior Manager
Senior Manager
User avatar
Joined: 10 Oct 2012
Posts: 331
Followers: 5

Kudos [?]: 129 [0], given: 25

Re: M06 #16 [#permalink] New post 18 Apr 2013, 16:11
mourinhogmat1 wrote:
If \frac{t}{u} = \frac{x}{y} and \frac{t}{y} = \frac{u}{x} and t , u , x , and y are non-zero integers, which of the following is true?

A. \frac{t}{u}=1
B. \frac{y}{x}=-1
C. t = u
D. t = \pm u
E. None of the above

A question to Bunuel or someone who actually wrote the test:

From the given equation we get ux=ty (1) and xt=uy (2)
subtracting 2 from 1 this we get x(u-t)= y (t-u) --> this gives us x=-y. This is option B.
So, why is option B wrong?


Multiply both the given equalities, we get t/u*t/y = x/y*u/x--> t^2 =u^2-->
D.
_________________

All that is equal and not --> inequalities-basics-154285.html

GMAT Club team member
User avatar
Joined: 02 Sep 2009
Posts: 12116
Followers: 1879

Kudos [?]: 10121 [0], given: 963

GMAT Tests User CAT Tests
Top Member of the Month
Re: M06 #16 [#permalink] New post 19 Apr 2013, 03:42
youngkacha wrote:
Bunuel wrote:
youngkacha wrote:
I'm stumped on this one too. Not clear at all.


Can you please tell me which part(s) of the solution didn't you understand?


I'm lost when you take the absolute value of t and u, yet u is +/- and t isn't.

Why is t = +/- u instead of being +/- t = +/- u?


|t|=|u| means that t=u (which is the same as -t=-u) or t=-u (which is the same as -t=u), so only two cases.
_________________

NEW TO MATH FORUM? PLEASE READ THIS: ALL YOU NEED FOR QUANT!!!

PLEASE READ AND FOLLOW: 11 Rules for Posting!!!

RESOURCES: [GMAT MATH BOOK]; 1. Triangles; 2. Polygons; 3. Coordinate Geometry; 4. Factorials; 5. Circles; 6. Number Theory; 7. Remainders; 8. Overlapping Sets; 9. PDF of Math Book; 10. Remainders

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. NEW!!! ,11 Mixed Questions NEW!!!, 12 Fresh Meat NEW!!!

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. NEW!!!, 11 New DS set. NEW!!!


What are GMAT Club Tests?
25 extra-hard Quant Tests

Find out what's new at GMAT Club - latest features and updates

Re: M06 #16   [#permalink] 19 Apr 2013, 03:42
    Similar topics Author Replies Last post
Similar
Topics:
 New posts 1 M06 #19 dczuchta 6 24 Sep 2008, 21:16
Popular new posts 19 M06 #08 scthakur 25 04 Nov 2008, 01:59
Popular new posts 7 Experts publish their posts in the topic m06 Q5 mbaobsessed 18 12 Nov 2008, 14:36
New posts M06 #16 bipolarbear 1 23 Jul 2009, 13:12
Display posts from previous: Sort by

M06 #16

  Question banks Downloads My Bookmarks Reviews  
Print view
First unread post

Moderator: Bunuel

Search for:


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

Powered by phpBB © phpBB Group and phpBB SEO

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®.

Main navigation

GMAT Resources

Partners

MBA Resources

www.gmac.com|www.mba.com