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

It is currently 15 Dec 2018, 05:53

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
  • Free GMAT Strategy Webinar

     December 15, 2018

     December 15, 2018

     07:00 AM PST

     09:00 AM PST

    Aiming to score 760+? Attend this FREE session to learn how to Define your GMAT Strategy, Create your Study Plan and Master the Core Skills to excel on the GMAT.
  • $450 Tuition Credit & Official CAT Packs FREE

     December 15, 2018

     December 15, 2018

     10:00 PM PST

     11:00 PM PST

    Get the complete Official GMAT Exam Pack collection worth $100 with the 3 Month Pack ($299)

If x 0, what is the value of (x^w/x^y)^4 ? (1) w = y

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

Hide Tags

Director
Director
User avatar
Joined: 25 Oct 2008
Posts: 511
Location: Kolkata,India
If x 0, what is the value of (x^w/x^y)^4 ? (1) w = y  [#permalink]

Show Tags

New post 28 Sep 2009, 04:50
4
00:00
A
B
C
D
E

Difficulty:

  35% (medium)

Question Stats:

61% (00:54) correct 39% (00:52) wrong based on 201 sessions

HideShow timer Statistics

If x ≠ 0, what is the value of \((x^w/x^y)^4\)?

(1) w = y

(2) x^2 = 1

Just wanted to get a clarification.
Stmt 1 is suff.
Stmt 2 i marked as insuff. cos x can have two values +1,-1..'cos in GMAT:
root16= 4
but x^2=16 means x=+4,-4 right?
So ans here should be A.

_________________

http://gmatclub.com/forum/countdown-beginshas-ended-85483-40.html#p649902

Math Expert
User avatar
V
Joined: 02 Aug 2009
Posts: 7107
Re: If x 0, what is the value of (x^w/x^y)^4 ? (1) w = y  [#permalink]

Show Tags

New post 28 Sep 2009, 05:07
hi tejal, u r right that x has 2 values +1 and -1.... but you have to take 4th power of whats in bracket .. so +1 or -1 will not make any diff... ans wud b always 1.... ans - D
_________________

1) Absolute modulus : http://gmatclub.com/forum/absolute-modulus-a-better-understanding-210849.html#p1622372
2)Combination of similar and dissimilar things : http://gmatclub.com/forum/topic215915.html
3) effects of arithmetic operations : https://gmatclub.com/forum/effects-of-arithmetic-operations-on-fractions-269413.html


GMAT online Tutor

Senior Manager
Senior Manager
avatar
B
Joined: 31 Aug 2009
Posts: 379
Location: Sydney, Australia
Re: If x 0, what is the value of (x^w/x^y)^4 ? (1) w = y  [#permalink]

Show Tags

New post 28 Sep 2009, 05:49
tejal777 wrote:
If x ≠ 0, what is the value of \((x^w/x^y)^4\)?

(1) w = y

(2) x^2 = 1

Just wanted to get a clarification.
Stmt 1 is suff.
Stmt 2 i marked as insuff. cos x can have two values +1,-1..'cos in GMAT:
root16= 4
but x^2=16 means x=+4,-4 right?
So ans here should be A.


1) is suff as you already noted.
2) regardless of if they are -1 or +1 once it is ^4 it will be positive. so also suff.

Hence D. What's OA?
Manager
Manager
avatar
Joined: 23 Sep 2009
Posts: 117
Re: If x 0, what is the value of (x^w/x^y)^4 ? (1) w = y  [#permalink]

Show Tags

New post 28 Sep 2009, 08:06
Ans: d)
As long as it is the powers of even number the answer is going to be 1.
_________________

Thanks,
VP

Senior Manager
Senior Manager
avatar
Joined: 30 Nov 2008
Posts: 468
Schools: Fuqua
Re: If x 0, what is the value of (x^w/x^y)^4 ? (1) w = y  [#permalink]

Show Tags

New post 29 Sep 2009, 08:50
My take is D.

Here is my explanation.

The equation in question stem can be simplfied as X^(4*(w-y)).

Clue 1: w = y ==> X ^ 0 = 1 We know the value of the expression in the question stem. Hence sufficient.

Clue 2: x^2 = 1 ==> X = +/-1 ==> 1 ^ even number = 1. ==> 1 ^ 2*2*(w-y) = 1. Again we know the value of the expression in the question stem. Hence sufficient.
Manager
Manager
User avatar
Status: Kitchener
Joined: 03 Oct 2013
Posts: 89
Location: Canada
Concentration: Finance, Finance
GPA: 2.9
WE: Education (Education)
Premium Member
Re: If x 0, what is the value of (x^w/x^y)^4 ? (1) w = y  [#permalink]

Show Tags

New post 30 Jan 2015, 14:27
Dear Bunuel, I want to ask what will be the value of (a/b)^- m/n equal to? Does it will be equal to (b/a)^n/m?
_________________

Click +1 Kudos if my post helped

Math Expert
User avatar
V
Joined: 02 Sep 2009
Posts: 51218
Re: If x 0, what is the value of (x^w/x^y)^4 ? (1) w = y  [#permalink]

Show Tags

New post 31 Jan 2015, 04:46
23a2012 wrote:
Dear Bunuel, I want to ask what will be the value of (a/b)^- m/n equal to? Does it will be equal to (b/a)^n/m?


\((\frac{a}{b})^{-\frac{m}{n}}=\frac{1}{(\frac{a}{b})^{\frac{m}{n}}}=\)

\(=(\frac{1}{\frac{a}{b}})^{\frac{m}{n}}=(\frac{b}{a})^{\frac{m}{n}}\).
_________________

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

Math Expert
User avatar
V
Joined: 02 Sep 2009
Posts: 51218
Re: If x 0, what is the value of (x^w/x^y)^4 ? (1) w = y  [#permalink]

Show Tags

New post 31 Jan 2015, 04:47
tejal777 wrote:
If x ≠ 0, what is the value of \((x^w/x^y)^4\)?

(1) w = y

(2) x^2 = 1

Just wanted to get a clarification.
Stmt 1 is suff.
Stmt 2 i marked as insuff. cos x can have two values +1,-1..'cos in GMAT:
root16= 4
but x^2=16 means x=+4,-4 right?
So ans here should be A.


Similar questions to practice:
if-x-0-what-is-the-value-of-x-p-x-q-166516.html
if-x-is-not-to-0-what-is-the-value-of-x-m-x-n-147963.html
if-x-0-what-is-the-value-of-sq-root-x-u-x-v-95674.html
_________________

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

Math Expert
User avatar
V
Joined: 02 Aug 2009
Posts: 7107
If x 0, what is the value of (x^w/x^y)^4 ? (1) w = y  [#permalink]

Show Tags

New post 31 Jan 2015, 04:49
tejal777 wrote:
If x ≠ 0, what is the value of \((x^w/x^y)^4\)?

(1) w = y

(2) x^2 = 1

Just wanted to get a clarification.
Stmt 1 is suff.
Stmt 2 i marked as insuff. cos x can have two values +1,-1..'cos in GMAT:
root16= 4
but x^2=16 means x=+4,-4 right?
So ans here should be A.



hi ... irrespective of the value of x as 1 or -1... the value will be 1 since the entire has the power of an even number,4..
_________________

1) Absolute modulus : http://gmatclub.com/forum/absolute-modulus-a-better-understanding-210849.html#p1622372
2)Combination of similar and dissimilar things : http://gmatclub.com/forum/topic215915.html
3) effects of arithmetic operations : https://gmatclub.com/forum/effects-of-arithmetic-operations-on-fractions-269413.html


GMAT online Tutor

EMPOWERgmat Instructor
User avatar
V
Status: GMAT Assassin/Co-Founder
Affiliations: EMPOWERgmat
Joined: 19 Dec 2014
Posts: 13087
Location: United States (CA)
GMAT 1: 800 Q51 V49
GRE 1: Q170 V170
Re: If x 0, what is the value of (x^w/x^y)^4 ? (1) w = y  [#permalink]

Show Tags

New post 31 Jan 2015, 12:22
Hi All,

This DS question can be solved with a mix of Number Property Rules and TESTing VALUES:

We're told that X cannot = 0. We're asked for the value of [(X^W)/(X^Y)]^4

While this may look "scary", it's actually based on some basic math rules/patterns. Notice how the "base" of both the numerator AND the denominator are the SAME....that matters....

Fact 1: W = Y

Let's TEST VALUES:

IF...
X = 1
W = 1
Y = 1

[(1^1)/(1^1)]^4 = (1/1)^4 = 1

IF....
X = 2
W = 3
Y = 3

[(2^3)/(2^3)]^4 = (8/8)^4 = (1/1)^4 = 1

From this work, you should notice that the fraction ALWAYS equals 1, so the answer will ALWAYS be 1^4 = 1. That will always occur regardless of what you TEST for the 3 variables (in Fact 1).
Fact 1 is SUFFICIENT

Fact 2: X^2 = 1

This tells us that X = 1 OR X = -1

Here's where some Number Property knowledge comes in handy.

+1 raised to ANY power = 1, so (1^W) and (1^Y) BOTH always = 1......and 1/1 = 1.....so 1^4 = 1

-1 raised to an EVEN power = 1
-1 raised to an ODD power = -1

While this might appear to yield different answer, you must remember what the specific question asks for....

With these two restrictions on the numerator and denominator, we have 4 possible calculations (and 2 possible outcomes):

(+1)/(-1) = -1
(-1)/(+1) = -1
(+1)/(+1) = 1
(-1)/(-1) = 1

(-1)^4 = 1
(+1)^4 = 1

So the answer is the SAME regardless.
Fact 2 is SUFFICIENT.

Final Answer:

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!*****

Non-Human User
User avatar
Joined: 09 Sep 2013
Posts: 9163
Premium Member
Re: If x 0, what is the value of (x^w/x^y)^4 ? (1) w = y  [#permalink]

Show Tags

New post 25 Sep 2018, 06:41
Hello from the GMAT Club BumpBot!

Thanks to another GMAT Club member, I have just discovered this valuable topic, yet it had no discussion for over a year. I am now bumping it up - doing my job. I think you may find it valuable (esp those replies with Kudos).

Want to see all other topics I dig out? Follow me (click follow button on profile). You will receive a summary of all topics I bump in your profile area as well as via email.
_________________

GMAT Books | GMAT Club Tests | Best Prices on GMAT Courses | GMAT Mobile App | Math Resources | Verbal Resources

GMAT Club Bot
Re: If x 0, what is the value of (x^w/x^y)^4 ? (1) w = y &nbs [#permalink] 25 Sep 2018, 06:41
Display posts from previous: Sort by

If x 0, what is the value of (x^w/x^y)^4 ? (1) w = y

  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®.