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

It is currently 21 Sep 2018, 18:39

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

If x^2 = 2y^3 and 2y = 4, what is the value of x^2 + y?

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

Hide Tags

Manager
Manager
avatar
Joined: 22 Mar 2012
Posts: 85
Location: United States (NY)
Concentration: General Management, Marketing
GPA: 3.1
WE: Accounting (Other)
If x^2 = 2y^3 and 2y = 4, what is the value of x^2 + y?  [#permalink]

Show Tags

New post Updated on: 24 Aug 2012, 21:39
2
00:00
A
B
C
D
E

Difficulty:

  5% (low)

Question Stats:

93% (00:31) correct 7% (00:56) wrong based on 113 sessions

HideShow timer Statistics

If x^2 = 2y^3 and 2y = 4, what is the value of x^2 + y?

A. -14
B. -2
C. 3
D. 6
E. 18

I understand how they came to the answer. But I'm confused as to why I can't replace 2y in the first equation with 4 to get x^2 = 64. That would give the equation x^2 + y, value of 66. Please tell me what am I missing? Attaching the screenshot of the question and answer. This is from the GMAC software.

Attachments

Gmac Problem.png
Gmac Problem.png [ 798.6 KiB | Viewed 4396 times ]


Originally posted by KAS1 on 24 Aug 2012, 13:36.
Last edited by Bunuel on 24 Aug 2012, 21:39, edited 1 time in total.
Edited the question.
Director
Director
User avatar
Joined: 22 Mar 2011
Posts: 604
WE: Science (Education)
Re: GMAC Problem  [#permalink]

Show Tags

New post 24 Aug 2012, 13:49
KAS1 wrote:
If x^2 = 2y^3 and 2y = 4, what is the value of x^2 + y?

    A. -14
    B. -2
    C. 3
    D. 6
    E. 18

I understand how they came to the answer. But I'm confused as to why I can't replace 2y in the first equation with 4 to get x^2 = 64. That would give the equation x^2 + y, value of 66. Please tell me what am I missing? Attaching the screenshot of the question and answer. This is from the GMAC software.


In the equation it is \(2y^3\) and not \((2y)^3.\) Therefore \(2y^3=2*2^3=16,\) because from \(2y=4,\)we obtain \(y=2.\)
_________________

PhD in Applied Mathematics
Love GMAT Quant questions and running.

Manager
Manager
avatar
Joined: 22 Mar 2012
Posts: 85
Location: United States (NY)
Concentration: General Management, Marketing
GPA: 3.1
WE: Accounting (Other)
Re: GMAC Problem  [#permalink]

Show Tags

New post 24 Aug 2012, 19:04
Wow!
Thanks so much. I have to pay attention to these little things on the exam.
Non-Human User
User avatar
Joined: 09 Sep 2013
Posts: 8131
Premium Member
Re: If x^2 = 2y^3 and 2y = 4, what is the value of x^2 + y?  [#permalink]

Show Tags

New post 05 Sep 2018, 11:11
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

Re: If x^2 = 2y^3 and 2y = 4, what is the value of x^2 + y? &nbs [#permalink] 05 Sep 2018, 11:11
Display posts from previous: Sort by

If x^2 = 2y^3 and 2y = 4, what is the value of x^2 + y?

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

Events & Promotions

PREV
NEXT


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®.