GMAT Question of the Day - Daily to your Mailbox; hard ones only

It is currently 13 Dec 2018, 17:42

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 in December
PrevNext
SuMoTuWeThFrSa
2526272829301
2345678
9101112131415
16171819202122
23242526272829
303112345
Open Detailed Calendar
  • GMATbuster's Weekly GMAT Quant Quiz, Tomorrow, Saturday at 9 AM PST

     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.
  • The winning strategy for 700+ on the GMAT

     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.

The product of x and y is a constant. If the value of x is increased b

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

Hide Tags

Math Expert
User avatar
V
Joined: 02 Sep 2009
Posts: 51185
The product of x and y is a constant. If the value of x is increased b  [#permalink]

Show Tags

New post 02 Feb 2016, 01:02
00:00
A
B
C
D
E

Difficulty:

  25% (medium)

Question Stats:

84% (01:23) correct 16% (01:11) wrong based on 76 sessions

HideShow timer Statistics

The product of x and y is a constant. If the value of x is increased by 50%, by what percentage must the value of y be decreased?

A. 50%
B. 40%
C. 33 1⁄3%
D. 25%
E. 12 1⁄2%

_________________

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?
Extra-hard Quant Tests with Brilliant Analytics

Verbal Forum Moderator
User avatar
V
Status: Greatness begins beyond your comfort zone
Joined: 08 Dec 2013
Posts: 2123
Location: India
Concentration: General Management, Strategy
Schools: Kelley '20, ISB '19
GPA: 3.2
WE: Information Technology (Consulting)
GMAT ToolKit User Reviews Badge CAT Tests
Re: The product of x and y is a constant. If the value of x is increased b  [#permalink]

Show Tags

New post 02 Feb 2016, 01:06
1
Product of x and y = xy
If the value of x is increased by 50% , value of y needs to be = xy/(1.5 x ) = 2/3 y
Decrease in value of y = y - 2/3 y = 1/3 y
% decrease in value of y = (1/3 y)/y * 100%
=33 1⁄3%

Answer C
_________________

When everything seems to be going against you, remember that the airplane takes off against the wind, not with it. - Henry Ford
The Moment You Think About Giving Up, Think Of The Reason Why You Held On So Long
+1 Kudos if you find this post helpful

Intern
Intern
avatar
Joined: 26 Jan 2016
Posts: 7
Re: The product of x and y is a constant. If the value of x is increased b  [#permalink]

Show Tags

New post 02 Feb 2016, 22:47
1
Say xy=a
Then 50% increase in x =150x/100=1.5x
Hence, 1.5xy=1.5a
To maintain the constant as a, we shud multiply it by 1/1.5;
So 1.5xy*1/1.5= a
1/1.5 is equivalent to 0.667
Therefore,y scud be decreased by 0.33
Or 33.33%
CEO
CEO
User avatar
P
Status: GMATINSIGHT Tutor
Joined: 08 Jul 2010
Posts: 2711
Location: India
GMAT: INSIGHT
WE: Education (Education)
Reviews Badge
Re: The product of x and y is a constant. If the value of x is increased b  [#permalink]

Show Tags

New post 03 Feb 2016, 00:25
Bunuel wrote:
The product of x and y is a constant. If the value of x is increased by 50%, by what percentage must the value of y be decreased?

A. 50%
B. 40%
C. 33 1⁄3%
D. 25%
E. 12 1⁄2%


x*y = constt.

Let x = y = 100 in beginning

i.e. x*y = 100*100 = 10000

x (100) ---becomes---> 1.5x (150)


i.e. 150*New 'y' = 10000
i.e. New 'y' = 10000/150 = 66.66

i.e. y decreases from 100 to 66.66 i.e. Decrease of 33.33%

Answer: option C
_________________

Prosper!!!
GMATinsight
Bhoopendra Singh and Dr.Sushma Jha
e-mail: info@GMATinsight.com I Call us : +91-9999687183 / 9891333772
Online One-on-One Skype based classes and Classroom Coaching in South and West Delhi
http://www.GMATinsight.com/testimonials.html

ACCESS FREE GMAT TESTS HERE:22 ONLINE FREE (FULL LENGTH) GMAT CAT (PRACTICE TESTS) LINK COLLECTION

LBS Thread Master
avatar
B
Joined: 13 Jan 2015
Posts: 102
Location: United Kingdom
Concentration: Other, General Management
Schools: LBS '19 (WL)
GMAT 1: 690 Q48 V36
Re: The product of x and y is a constant. If the value of x is increased b  [#permalink]

Show Tags

New post 03 Feb 2016, 00:47
Let x be 4 and y be 6, therefore xy = 24

50% increase in X is 4 x1.5 = 6
To maintain the constant of 24, Y will need to reduce to 4
so to calculate the % decrease in y, we use New Value - Old Value / Old Value
% Decrease in Y = 4-6/6 => 2/6 => 1/3
Convert 1/3 to % => 33.3%
EMPOWERgmat Instructor
User avatar
V
Status: GMAT Assassin/Co-Founder
Affiliations: EMPOWERgmat
Joined: 19 Dec 2014
Posts: 13081
Location: United States (CA)
GMAT 1: 800 Q51 V49
GRE 1: Q170 V170
Re: The product of x and y is a constant. If the value of x is increased b  [#permalink]

Show Tags

New post 04 Feb 2016, 22:20
Hi All,

This question is based on a 'math truism' that shows up most often in certain types of "Distance Formula" questions. Here's a link to a question that's based on the exact SAME idea:

john-would-have-reduced-the-time-it-took-him-to-drive-from-his-home-to-210670.html?hilit=truism

GMAT assassins aren't born, they're made,
Rich
_________________

760+: Learn What GMAT Assassins Do to Score at the Highest Levels
Contact Rich at: Rich.C@empowergmat.com

Rich Cohen

Co-Founder & GMAT Assassin

Special Offer: Save $75 + GMAT Club Tests Free
  Official GMAT Exam Packs + 70 Pt. Improvement Guarantee
www.empowergmat.com/

*****Select EMPOWERgmat Courses now include ALL 6 Official GMAC CATs!*****

Board of Directors
User avatar
P
Status: QA & VA Forum Moderator
Joined: 11 Jun 2011
Posts: 4276
Location: India
GPA: 3.5
WE: Business Development (Commercial Banking)
GMAT ToolKit User Premium Member CAT Tests
The product of x and y is a constant. If the value of x is increased b  [#permalink]

Show Tags

New post 21 Aug 2018, 21:13
Bunuel wrote:
The product of x and y is a constant. If the value of x is increased by 50%, by what percentage must the value of y be decreased?

A. 50%
B. 40%
C. 33 1⁄3%
D. 25%
E. 12 1⁄2%


Let \(x = 10\) and \(y = 10\) and \(xy = 100\)

If \(x\) is increased by \(50\)% its value is \(15\)

So, The value of \(y\) is \(\frac{100}{15} = 6.67\)

So, The value of y must be decreased by 33 1⁄3% , Answer must be (C)
_________________

Thanks and Regards

Abhishek....

PLEASE FOLLOW THE RULES FOR POSTING IN QA AND VA FORUM AND USE SEARCH FUNCTION BEFORE POSTING NEW QUESTIONS

How to use Search Function in GMAT Club | Rules for Posting in QA forum | Writing Mathematical Formulas |Rules for Posting in VA forum | Request Expert's Reply ( VA Forum Only )

Senior Manager
Senior Manager
User avatar
P
Joined: 18 Jul 2018
Posts: 497
Location: India
Concentration: Finance, Marketing
WE: Engineering (Energy and Utilities)
Premium Member Reviews Badge CAT Tests
Re: The product of x and y is a constant. If the value of x is increased b  [#permalink]

Show Tags

New post 21 Aug 2018, 21:47
The ans is C 33\(\frac{1}{3}\)
Attachments

File comment: This attachment would be useful in solving such problems
IMG_20180822_110854.jpg
IMG_20180822_110854.jpg [ 129.71 KiB | Viewed 1235 times ]


_________________

When you want something, the whole universe conspires in helping you achieve it.

GMAT Club Bot
Re: The product of x and y is a constant. If the value of x is increased b &nbs [#permalink] 21 Aug 2018, 21:47
Display posts from previous: Sort by

The product of x and y is a constant. If the value of x is increased b

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


Copyright

GMAT Club MBA Forum Home| About| Terms and Conditions and Privacy Policy| 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®.