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

It is currently 15 Oct 2019, 02:28

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

Is 2a < a^2 + b ?

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

Hide Tags

Find Similar Topics 
Senior Manager
Senior Manager
User avatar
V
Joined: 22 Feb 2018
Posts: 420
Is 2a < a^2 + b ?  [#permalink]

Show Tags

New post 26 Oct 2018, 10:33
2
00:00
A
B
C
D
E

Difficulty:

  45% (medium)

Question Stats:

64% (01:26) correct 36% (01:39) wrong based on 37 sessions

HideShow timer Statistics

Is \(2a < a^2 + b\) ?

(1) \(0 < a < 2\)
(2) \(-2 < b < 0\)

_________________
Good, good Let the kudos flow through you
GMAT Club Legend
GMAT Club Legend
User avatar
V
Joined: 12 Sep 2015
Posts: 4000
Location: Canada
Re: Is 2a < a^2 + b ?  [#permalink]

Show Tags

New post 26 Oct 2018, 11:35
2
Top Contributor
Princ wrote:
Is \(2a < a^2 + b\) ?

(1) \(0 < a < 2\)
(2) \(-2 < b < 0\)


Target question: Is 2a < a² + b

Statement 1: 0 < a < 2
No information about b, so statement 1 is NOT SUFFICIENT

Statement 2: -2 < b < 0
No information about a, so statement 2 is NOT SUFFICIENT

Statements 1 and 2 combined
It may help to REPHRASE the target question by getting the a's on one side of the equation
Take: Is 2a < a² + b?
Subtract a² from both sides to get: Is 2a - a² < b?
Factor left side to get: Is a(2 - a) < b?

Since 0 < a < 2, we know that a is POSITIVE, and we know that (2 - a) is POSITIVE
Also, if -2 < b < 0, then we know that b is NEGATIVE

So, our target question becomes: Is (POSITIVE)(POSITIVE) < NEGATIVE?
Simplify left side to get: Is POSITIVE < NEGATIVE?
The answer to this REPHRASED question is "NO, it is definitely NOT the case that POSITIVE < NEGATIVE"
Since we can answer the target question with certainty, the combined statements are SUFFICIENT

Answer: C

Cheers,
Brent
_________________
Test confidently with gmatprepnow.com
Image
GMAT Club Bot
Re: Is 2a < a^2 + b ?   [#permalink] 26 Oct 2018, 11:35
Display posts from previous: Sort by

Is 2a < a^2 + b ?

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





Powered by phpBB © phpBB Group | Emoji artwork provided by EmojiOne