It is currently 17 Oct 2017, 10:30

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 (xy)^(1/2) = 3, what is the value of x ?

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

Hide Tags

Expert Post
Math Expert
User avatar
V
Joined: 02 Sep 2009
Posts: 41873

Kudos [?]: 128564 [0], given: 12180

If (xy)^(1/2) = 3, what is the value of x ? [#permalink]

Show Tags

New post 17 Sep 2017, 03:04
00:00
A
B
C
D
E

Difficulty:

  45% (medium)

Question Stats:

51% (00:36) correct 49% (00:29) wrong based on 65 sessions

HideShow timer Statistics

Kudos [?]: 128564 [0], given: 12180

Intern
Intern
avatar
B
Joined: 26 Jul 2017
Posts: 18

Kudos [?]: 10 [0], given: 25

Location: India
Re: If (xy)^(1/2) = 3, what is the value of x ? [#permalink]

Show Tags

New post 17 Sep 2017, 03:11
Bunuel wrote:
If \(\sqrt{xy} = 3\), what is the value of x ?

(1) x = y
(2) y = 3



1. x = y gives us \sqrt{x^2} = 3 -----> |x| = 3 ----------> x = +3 or -3. Hence insufficient.

2. y =3 gives us \sqrt{x3} = 3 ---- on squaring both sides we get 3x = 9 --------> hence x=3. Sufficient

Answer is (B)

Kudos [?]: 10 [0], given: 25

Intern
Intern
avatar
B
Joined: 25 Apr 2017
Posts: 10

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

Re: If (xy)^(1/2) = 3, what is the value of x ? [#permalink]

Show Tags

New post 17 Sep 2017, 03:20
I think the answer is B

1, X=Y-> /x/=3 -> x = 3 or x = -3 -> insufficient
2, y = 3 -> 3x = 9 -> x=3 -> sufficient

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

Manager
Manager
User avatar
B
Status: love the club...
Joined: 24 Mar 2015
Posts: 168

Kudos [?]: 13 [0], given: 400

Re: If (xy)^(1/2) = 3, what is the value of x ? [#permalink]

Show Tags

New post 24 Sep 2017, 03:45
Bunuel wrote:
If \(\sqrt{xy} = 3\), what is the value of x ?

(1) x = y
(2) y = 3



hi

√xy = 3
So
| xy | = 9

statement 1 says x = y
x can be -3 or 3
so, -3 = -3 or 3 = 3, not sufficient

statement 2 says
y = 3

| 3x | = 9

x = 3
or

x = -3

not sufficient ...

statement 1 and 2 taken together:

x = 3, sufficient

C

thanks in advance ...

Kudos [?]: 13 [0], given: 400

Manager
Manager
User avatar
B
Status: love the club...
Joined: 24 Mar 2015
Posts: 168

Kudos [?]: 13 [0], given: 400

Re: If (xy)^(1/2) = 3, what is the value of x ? [#permalink]

Show Tags

New post 25 Sep 2017, 02:06
Bunuel wrote:
If \(\sqrt{xy} = 3\), what is the value of x ?

(1) x = y
(2) y = 3



hi Bunuel

looking forward to your solution to the question

thanks

Kudos [?]: 13 [0], given: 400

Expert Post
Math Expert
User avatar
V
Joined: 02 Sep 2009
Posts: 41873

Kudos [?]: 128564 [0], given: 12180

Re: If (xy)^(1/2) = 3, what is the value of x ? [#permalink]

Show Tags

New post 25 Sep 2017, 03:00
gmatcracker2017 wrote:
Bunuel wrote:
If \(\sqrt{xy} = 3\), what is the value of x ?

(1) x = y
(2) y = 3



hi Bunuel

looking forward to your solution to the question

thanks


If \(\sqrt{xy} = 3\), what is the value of x ?

(1) x = y:

\(\sqrt{x^2} = 3\);

Square: \(x^2 = 9\);

x = 3 or x = -3. Not sufficient.


(2) y = 3:

\(\sqrt{3x} = 3\);

Square: \(3x = 9\);

x = 3. Sufficient.

Answer: B.

P.S. Note that x = -3 is not a valid solution for (2) because in this case \(\sqrt{xy} = \sqrt{-9}\), which is undefined and not equal to 3 as given in the stem.
_________________

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

Kudos [?]: 128564 [0], given: 12180

Manager
Manager
User avatar
B
Status: love the club...
Joined: 24 Mar 2015
Posts: 168

Kudos [?]: 13 [0], given: 400

Re: If (xy)^(1/2) = 3, what is the value of x ? [#permalink]

Show Tags

New post 25 Sep 2017, 04:09
Bunuel wrote:
gmatcracker2017 wrote:
Bunuel wrote:
If \(\sqrt{xy} = 3\), what is the value of x ?

(1) x = y
(2) y = 3



hi Bunuel

looking forward to your solution to the question

thanks


If \(\sqrt{xy} = 3\), what is the value of x ?

(1) x = y:

\(\sqrt{x^2} = 3\);

Square: \(x^2 = 9\);

x = 3 or x = -3. Not sufficient.


(2) y = 3:

\(\sqrt{3x} = 3\);

Square: \(3x = 9\);

x = 3. Sufficient.

Answer: B.

P.S. Note that x = -3 is not a valid solution for (2) because in this case \(\sqrt{xy} = \sqrt{-9}\), which is undefined and not equal to 3 as given in the stem.


thanks man
we cannot take square roots over negative numbers

Kudos [?]: 13 [0], given: 400

Manager
Manager
User avatar
S
Joined: 22 Nov 2016
Posts: 199

Kudos [?]: 36 [0], given: 38

Location: United States
Concentration: Leadership, Strategy
GPA: 3.4
Reviews Badge
Re: If (xy)^(1/2) = 3, what is the value of x ? [#permalink]

Show Tags

New post 26 Sep 2017, 16:48
Can we square the question stem to get xy = 9 and then proceed?
_________________

Kudosity killed the cat but your kudos can save it.

Kudos [?]: 36 [0], given: 38

Expert Post
Math Expert
User avatar
V
Joined: 02 Sep 2009
Posts: 41873

Kudos [?]: 128564 [0], given: 12180

Re: If (xy)^(1/2) = 3, what is the value of x ? [#permalink]

Show Tags

New post 26 Sep 2017, 21:11

Kudos [?]: 128564 [0], given: 12180

Re: If (xy)^(1/2) = 3, what is the value of x ?   [#permalink] 26 Sep 2017, 21:11
Display posts from previous: Sort by

If (xy)^(1/2) = 3, what is the value of x ?

  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®.