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

It is currently 18 Dec 2018, 07:18

Expecting Soon:

R1 Admission Decisions from McCombs - Join Chat Room for Latest Updates


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
  • Happy Christmas 20% Sale! Math Revolution All-In-One Products!

     December 20, 2018

     December 20, 2018

     10:00 PM PST

     11:00 PM PST

    This is the most inexpensive and attractive price in the market. Get the course now!
  • Key Strategies to Master GMAT SC

     December 22, 2018

     December 22, 2018

     07:00 AM PST

     09:00 AM PST

    Attend this webinar to learn how to leverage Meaning and Logic to solve the most challenging Sentence Correction Questions.

If (x - 3)^2/(2x + 15) = 3, what is the product of the possible values

  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: 51280
If (x - 3)^2/(2x + 15) = 3, what is the product of the possible values  [#permalink]

Show Tags

New post 10 Aug 2018, 02:55
00:00
A
B
C
D
E

Difficulty:

  65% (hard)

Question Stats:

60% (01:56) correct 40% (01:55) wrong based on 65 sessions

HideShow timer Statistics

SC Moderator
User avatar
P
Joined: 30 Jan 2015
Posts: 673
Location: India
Concentration: Operations, Marketing
GPA: 3.5
If (x - 3)^2/(2x + 15) = 3, what is the product of the possible values  [#permalink]

Show Tags

New post Updated on: 10 Aug 2018, 12:21
Bunuel wrote:
If \(\frac{(x - 3)^2}{(2x + 15)} = 3\), what is the product of the possible values of x?

(x - 3)^2 / (2x + 15) = 3
x^2 - 6x + 9 = 6x + 45
x^2 - 12x - 36 = 0
Product of roots of equation of form ax^2+bx+c = 0 is c/a
Therefore,
Product = -36/1 = -36

Hence, A.
_________________

The few, the fearless !

Thanks :-)


Originally posted by sudarshan22 on 10 Aug 2018, 03:21.
Last edited by sudarshan22 on 10 Aug 2018, 12:21, edited 2 times in total.
Director
Director
User avatar
P
Status: Learning stage
Joined: 01 Oct 2017
Posts: 931
WE: Supply Chain Management (Energy and Utilities)
Premium Member
Re: If (x - 3)^2/(2x + 15) = 3, what is the product of the possible values  [#permalink]

Show Tags

New post 10 Aug 2018, 03:22
Bunuel wrote:
If \(\frac{(x - 3)^2}{(2x + 15)} = 3\), what is the product of the possible values of x?


A. −36
B. −6
C. 4
D. 6
E. 36


\(\frac{(x - 3)^2}{(2x + 15)} = 3\)
Or,\(\frac{\left(x-3\right)^2}{2x+15}\left(2x+15\right)=3\left(2x+15\right)\)
Or, \(\left(x-3\right)^2=3\left(2x+15\right)\)
Or, \(x=6\left(1+\sqrt{2}\right),\:x=6\left(1-\sqrt{2}\right)\)

\(Product=36*(1+\sqrt{2})(1+\sqrt{2})=36*(1^2-(\sqrt{2})^2)=36(1-2)=36*(-1)=-36\)

Ans. (A)
_________________

Regards,

PKN

Rise above the storm, you will find the sunshine

Director
Director
User avatar
P
Joined: 31 Oct 2013
Posts: 898
Concentration: Accounting, Finance
GPA: 3.68
WE: Analyst (Accounting)
Re: If (x - 3)^2/(2x + 15) = 3, what is the product of the possible values  [#permalink]

Show Tags

New post 10 Aug 2018, 03:29
sudarshan22 wrote:
Bunuel wrote:
If \(\frac{(x - 3)^2}{(2x + 15)} = 3\), what is the product of the possible values of x?

(x - 3)^2 / (2x + 15) = 3
x^2 - 6x + 9 = 6x + 45
x^2 - 12x + 36 = 0
On solving x = 6, -6
Product = -36

Hence, A.



Bro, how did u get + 36.
SC Moderator
User avatar
P
Joined: 30 Jan 2015
Posts: 673
Location: India
Concentration: Operations, Marketing
GPA: 3.5
Re: If (x - 3)^2/(2x + 15) = 3, what is the product of the possible values  [#permalink]

Show Tags

New post 10 Aug 2018, 03:33
selim wrote:
sudarshan22 wrote:
Bunuel wrote:
If \(\frac{(x - 3)^2}{(2x + 15)} = 3\), what is the product of the possible values of x?

(x - 3)^2 / (2x + 15) = 3
x^2 - 6x + 9 = 6x + 45
x^2 - 12x + 36 = 0
On solving x = 6, -6
Product = -36

Hence, A.



Bro, how did u get + 36.


Typo it was, answer is still the same. Thanks again.
_________________

The few, the fearless !

Thanks :-)

Intern
Intern
avatar
B
Joined: 30 May 2018
Posts: 9
If (x - 3)^2/(2x + 15) = 3, what is the product of the possible values  [#permalink]

Show Tags

New post 10 Aug 2018, 03:42
1
PKN wrote:
Bunuel wrote:
If \(\frac{(x - 3)^2}{(2x + 15)} = 3\), what is the product of the possible values of x?


A. −36
B. −6
C. 4
D. 6
E. 36


\(\frac{(x - 3)^2}{(2x + 15)} = 3\)
Or,\(\frac{\left(x-3\right)^2}{2x+15}\left(2x+15\right)=3\left(2x+15\right)\)
Or, \(\left(x-3\right)^2=3\left(2x+15\right)\)
Or, \(x=6\left(1+\sqrt{2}\right),\:x=6\left(1-\sqrt{2}\right)\)

\(Product=36*(1+\sqrt{2})(1+\sqrt{2})=36*(1^2-(\sqrt{2})^2)=36(1-2)=36*(-1)=-36\)

Ans. (A)

Instead of finding roots and multiplying them, we can get product directly..

x^2-6x+9 = 6x+45
x^2-12x-36 = 0
Product of roots for equation ax^2+bx+c=0 is c/a
So, product of roots = -36
Hence option A
This can save time in exam

Posted from my mobile device
Rice (Jones) Thread Master
User avatar
B
Joined: 18 Jun 2018
Posts: 84
Location: United States (AZ)
Concentration: Finance, Healthcare
CAT Tests
If (x - 3)^2/(2x + 15) = 3, what is the product of the possible values  [#permalink]

Show Tags

New post 10 Aug 2018, 05:16
1
I am confused sudarshan22. Thought the roots should be 6(1+√2) and 6(1-√2) with product of -36 (A). Not 6 and -6 even though their product is -36.

sudarshan22 wrote:
Bunuel wrote:
If \(\frac{(x - 3)^2}{(2x + 15)} = 3\), what is the product of the possible values of x?

(x - 3)^2 / (2x + 15) = 3
x^2 - 6x + 9 = 6x + 45
x^2 - 12x - 36 = 0
On solving x = 6, -6
Product = -36

Hence, A.
Senior Manager
Senior Manager
User avatar
P
Joined: 18 Jun 2018
Posts: 255
Premium Member CAT Tests
If (x - 3)^2/(2x + 15) = 3, what is the product of the possible values  [#permalink]

Show Tags

New post 10 Aug 2018, 05:53
1
funsogu wrote:
I am confused sudarshan22. Thought the roots should be 6(1+√2) and 6(1-√2) with product of -36 (A). Not 6 and -6 even though their product is -36.

sudarshan22 wrote:
Bunuel wrote:
If \(\frac{(x - 3)^2}{(2x + 15)} = 3\), what is the product of the possible values of x?

(x - 3)^2 / (2x + 15) = 3
x^2 - 6x + 9 = 6x + 45
x^2 - 12x - 36 = 0
On solving x = 6, -6
Product = -36

Hence, A.

funsogu
you are right
\(\frac{(x - 3)^2}{(2x + 15)} = 3\)
\((x - 3)^2=3(2x + 15)\)
\(x^2 + 9 -6x =6x +45\)
\(x^2 + 9-45 -6x-6x =0\)
\(x^2 -12x -36 =0\)

Roots \(=\frac {-b±\sqrt{b^2-4ac}}{2a}\) where \(ax^2+bx+c=0\)
\(a=1,b=-12,c=-36\)
Roots\(= \frac{12+ \sqrt{(-12)^2 - 4*1*(-36)}}{2*1}; \frac{12- \sqrt{(-12)^2 - 4*1*(-36)}}{2*1}\)
Roots\(= \frac{12+ \sqrt{2*12^2}}{2}; \frac{12- \sqrt{2*12^2}}{2}\)
Roots\(= 6(1+ \sqrt{2});6 (1- \sqrt{2})\)

It is better to follow the method as followed by pradeep15793


Quote:
Instead of finding roots and multiplying them, we can get product directly.
\(x^2-6x+9 = 6x+45\)
\(x^2-12x-36 = 0\)
Product of roots for equation \(ax^2+bx+c=0\) is \(\frac{c}{a}\)
So, product of roots\(= -36\)
Hence option A
This can save time in exam
Board of Directors
User avatar
P
Status: QA & VA Forum Moderator
Joined: 11 Jun 2011
Posts: 4280
Location: India
GPA: 3.5
WE: Business Development (Commercial Banking)
GMAT ToolKit User Premium Member CAT Tests
Re: If (x - 3)^2/(2x + 15) = 3, what is the product of the possible values  [#permalink]

Show Tags

New post 10 Aug 2018, 06:53
Bunuel wrote:
If \(\frac{(x - 3)^2}{(2x + 15)} = 3\), what is the product of the possible values of x?


A. −36
B. −6
C. 4
D. 6
E. 36

\(\frac{(x - 3)^2}{(2x + 15)} = 3\).

Or, \(x^2 - 6x + 9 = 6x + 45\)

Or, \(x^2 - 12x -36 =\)

x must be +6 & -6 , Thus the product of x will be - 36 , Answer must be (A) -36
_________________

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 )

SC Moderator
User avatar
P
Joined: 30 Jan 2015
Posts: 673
Location: India
Concentration: Operations, Marketing
GPA: 3.5
Re: If (x - 3)^2/(2x + 15) = 3, what is the product of the possible values  [#permalink]

Show Tags

New post 10 Aug 2018, 12:24
funsogu Bismarck
Thanks for rectifying the blunder, it was a mistake indeed.
As mentioned Pradeep's approach seems to to be more legit, I have updated my post accordingly.
_________________

The few, the fearless !

Thanks :-)

GMAT Club Bot
Re: If (x - 3)^2/(2x + 15) = 3, what is the product of the possible values &nbs [#permalink] 10 Aug 2018, 12:24
Display posts from previous: Sort by

If (x - 3)^2/(2x + 15) = 3, what is the product of the possible values

  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®.