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

It is currently 23 Oct 2019, 17:07

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 a < b? (1) a^3 = ab (2) |b| > |a|

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

Hide Tags

Find Similar Topics 
Math Expert
User avatar
V
Joined: 02 Sep 2009
Posts: 58464
Is a < b? (1) a^3 = ab (2) |b| > |a|  [#permalink]

Show Tags

New post 14 Jun 2018, 21:07
2
9
00:00
A
B
C
D
E

Difficulty:

  95% (hard)

Question Stats:

40% (01:58) correct 60% (01:38) wrong based on 156 sessions

HideShow timer Statistics

Intern
Intern
User avatar
B
Joined: 01 Jan 2018
Posts: 43
Re: Is a < b? (1) a^3 = ab (2) |b| > |a|  [#permalink]

Show Tags

New post 14 Jun 2018, 21:23
OA - E

Statement 1: a^3 = ab

If a = +ve then b should be +ve. And many values will satisfy this condition. For ex a = 2 and b = 4. In this case a < b.

If a = -ve then b should be positive. Again many values would satisfy this condition. For ex a = -2 and b = 4. In this case too a < b.

But if a = 0, then B can be any value. b = -1 or 1. In one case a>b and in other case a < b. No clear solution.

Statement 2: |b| > |a|

Lets take two values. a = -2 and b = -3. Since in mod b would be greater than a; however a is greater than b.
if a = 2 and b = 3, then b is greater than a. No clear solution.

Combining both.

If a = 0. Then b could be any value. Could be 2 or -2.
For positive value of b it'd be greater than a
but for negative value of b it'd be lesser than a.
Hence no clear solution even after combining.
e-GMAT Representative
User avatar
V
Joined: 04 Jan 2015
Posts: 3092
Re: Is a < b? (1) a^3 = ab (2) |b| > |a|  [#permalink]

Show Tags

New post 14 Jun 2018, 22:08

Solution



To find:
    • Whether a < b?

Analysing Statement 1
    • As per the information given in statement 1, a^3 = ab
      o Or, a^3 – ab = 0
      Or, a (a^2 – b) = 0

    • Now, if we assume a = 0, in that case b can be either > 0 or < 0 or = 0
    • As all the possibilities exist for b, we can’t say whether a < b

Hence, statement 1 is not sufficient to answer

Analysing Statement 2
    • As per the information given in statement 2, |b| > |a|
    • If we assume a = 0, then for any negative or positive value of b, |b| > |a|
    • As b can be both positive or negative compared to a = 0, we can’t say whether a < b

Hence, statement 2 is not sufficient to answer

Combining Both Statements
Considering the combined data available in both the statements, we can write
    • For a = 0, b can have either positive or negative value
    • Therefore, we can’t say whether a < b

Hence, the correct answer is option E.

Answer: E
_________________
Manager
Manager
avatar
B
Joined: 03 Apr 2018
Posts: 65
Location: United Arab Emirates
GMAT 1: 700 Q49 V35
GPA: 4
GMAT ToolKit User Reviews Badge
Re: Is a < b? (1) a^3 = ab (2) |b| > |a|  [#permalink]

Show Tags

New post 15 Jun 2018, 02:49
1
it should be e

from 1st st. a can be 0 or a square can be equal to b
from 2nd, b can either be less than a or more than a
Math Expert
avatar
V
Joined: 02 Aug 2009
Posts: 8023
Re: Is a < b? (1) a^3 = ab (2) |b| > |a|  [#permalink]

Show Tags

New post 15 Jun 2018, 05:53
Bunuel wrote:
Is a < b?

(1) a^3 = ab

(2) |b| > |a|


Source: 4Gmat


1) a^3=ab...
a(a^2-b)=0
So either a=0 or a^2=b or both are 0
Insufficient
2) |b|>|a|
So if b>0, yes a<b
If b<0, no
Insufficient

Combined..
We still can't say if b is positive or negative but b is not equal to 0..
Insufficient
_________________
Intern
Intern
User avatar
B
Joined: 29 Jan 2015
Posts: 49
Location: India
Concentration: Marketing, Entrepreneurship
GPA: 3.7
WE: Information Technology (Internet and New Media)
CAT Tests
Re: Is a < b? (1) a^3 = ab (2) |b| > |a|  [#permalink]

Show Tags

New post 20 Jun 2018, 04:37
Answer would be E , I think.
a^3 = ab
a^2 = b

as bcz square can't be negative so b must be positive.
but a can be positve or negative so we can't decide. ( for taking 1 a can be equal to b or by taking any number b is always greater than a . )

| b | > | a |

b > a ( when taking + ve)

or

-b > -a ( when taking -ve )
b < a so we can't decide.
GMAT Club Legend
GMAT Club Legend
User avatar
D
Joined: 18 Aug 2017
Posts: 5043
Location: India
Concentration: Sustainability, Marketing
GPA: 4
WE: Marketing (Energy and Utilities)
GMAT ToolKit User Premium Member
Re: Is a < b? (1) a^3 = ab (2) |b| > |a|  [#permalink]

Show Tags

New post 04 Mar 2019, 00:45
Bunuel wrote:
Is a < b?

(1) a^3 = ab

(2) |b| > |a|


Source: 4Gmat


#1
a^3=ab
or say
a^2=b
now a= +/-2 and b=4
in sufficient
#2
|b| > |a|
we can have +/- values of b so in sufficient to conclude that b>a

from 1& 2
we cannot derive anything in common to conclude b>a
IMO E
GMAT Club Bot
Re: Is a < b? (1) a^3 = ab (2) |b| > |a|   [#permalink] 04 Mar 2019, 00:45
Display posts from previous: Sort by

Is a < b? (1) a^3 = ab (2) |b| > |a|

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





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