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

It is currently 11 Dec 2018, 08:10

Starting NOW!

YouTube Live with Cornell Johnson - Join HERE  |  HBS Chat - Decisions at Noon ET  |  Haas Chat  HaaS calling admits |  Darden Chat 


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 Prep Hour

     December 11, 2018

     December 11, 2018

     09:00 PM EST

     10:00 PM EST

    Strategies and techniques for approaching featured GMAT topics. December 11 at 9 PM EST.
  • 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.

Is integer x<−20?

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

Hide Tags

Manager
Manager
avatar
Joined: 06 Jun 2014
Posts: 90
Location: United States
Concentration: Finance, General Management
GMAT 1: 450 Q27 V21
GPA: 3.47
GMAT ToolKit User
Is integer x<−20?  [#permalink]

Show Tags

New post 06 Feb 2016, 17:48
1
1
00:00
A
B
C
D
E

Difficulty:

  45% (medium)

Question Stats:

75% (02:06) correct 25% (01:48) wrong based on 170 sessions

HideShow timer Statistics

Is integer x<−20?

1) \(x^2+40x+391=0\)

2) \(x^2= 529\)
SVP
SVP
avatar
B
Joined: 06 Nov 2014
Posts: 1879
Re: Is integer x<−20?  [#permalink]

Show Tags

New post 06 Feb 2016, 21:17
1
zxcvbnmas wrote:
Is integer x<−20?

1) \(x^2+40x+391=0\)

2) \(x^2= 529\)


Statement 1: \(x^2+40x+391=0\)
\(x^2+23x +17x+391=0\)
(x+23)(x+17) = 0

Therefore x = -23 or x = -17
Insufficient

Statement 2: \(x^2= 529\)
x = -23 or 23
Insufficeint

From Statement 1 and 2, we know that x = -23
Sufficient. Option C
Manager
Manager
avatar
S
Joined: 30 May 2017
Posts: 66
Concentration: Finance, General Management
GMAT 1: 690 Q47 V38
GPA: 3.23
Re: Is integer x<−20?  [#permalink]

Show Tags

New post 29 Jun 2017, 14:51
Are there any tips for finding the square root of large numbers like this?
_________________

Veritas Prep 6/18/17 600 Q:38 V:35 IR:5
Veritas Prep 6/29/17 620 Q:43 V:33 IR:4
Manhattan 7/12/17 640 Q:42 V:35 IR:2.4
Veritas Prep 7/27/17 640 Q:41 V:37 IR:4
Manhattan 8/9/17 670 Q:44 V:37 IR:3
Veritas Prep 8/21/17 660 Q:45 V:36 IR:7
GMAT Prep 8/23/17 700 Q:47 V:38 IR:8
GMAT Prep 8/27/17 730 Q:49 V:40 IR:8
Veritas Prep 8/30/17 690 Q:47 V:37 IR:8

Senior Manager
Senior Manager
avatar
G
Joined: 24 Apr 2016
Posts: 331
Re: Is integer x<−20?  [#permalink]

Show Tags

New post 29 Jun 2017, 15:08
Statement 2: \(x^2=529\)

x can be -23 or +23

As this statement gives two different values, This statement is not sufficient

Statement 1:\(x^2+40x+391=\)0

Above can be written as (x+23)(x+17)=0

So x can be -23 or -17

As this statement gives two different values, This statement is not sufficient

Combining both statements we get x=-23

Answer is C
Senior Manager
Senior Manager
avatar
G
Joined: 24 Apr 2016
Posts: 331
Is integer x<−20?  [#permalink]

Show Tags

New post 29 Jun 2017, 15:15
1
Smokeybear00 wrote:
Are there any tips for finding the square root of large numbers like this?


Smokeybear00

To know what the square root of 529, you can say start with squaring a number which can be done easily in your head and gets u closer to the correct number

Lets start with 10. Square of 10 gives 100. so we have way ahead to go
Lets straight go to 20. Square of 20 gives 400. So we are near by,
Let see 25. Square of 25 gives 625. So we know the number is between 20 and 25.

Now we know see the last digit of 529 is 9, so the unit's digit of the number we are looking for should be with 3 or 9. Between 20 and 25 only 23 satisfies this. So 23 is the number we are looking for.

This is how I try to do. I am sure others might have a better way.

The other thing i suggest is memorize the squares from 1-50. This will help a long way.
Non-Human User
User avatar
Joined: 09 Sep 2013
Posts: 9116
Premium Member
Re: Is integer x<−20?  [#permalink]

Show Tags

New post 23 Aug 2018, 10:54
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: Is integer x<−20? &nbs [#permalink] 23 Aug 2018, 10:54
Display posts from previous: Sort by

Is integer x<−20?

  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®.