Last visit was: 24 Apr 2024, 23:55 It is currently 24 Apr 2024, 23:55

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
SORT BY:
Date
Tags:
Show Tags
Hide Tags
Math Expert
Joined: 02 Sep 2009
Posts: 92901
Own Kudos [?]: 618865 [5]
Given Kudos: 81588
Send PM
avatar
Manager
Manager
Joined: 12 Jun 2015
Posts: 71
Own Kudos [?]: 70 [1]
Given Kudos: 104
Send PM
RC & DI Moderator
Joined: 02 Aug 2009
Status:Math and DI Expert
Posts: 11172
Own Kudos [?]: 31897 [2]
Given Kudos: 290
Send PM
avatar
Manager
Manager
Joined: 12 Jun 2015
Posts: 71
Own Kudos [?]: 70 [0]
Given Kudos: 104
Send PM
Re: Considering the positions on the number line above, which of the follo [#permalink]
Very true.

I had taken both the conditions into account before I cancelled the options A and B

Also , when x < x^3

x can either lie between -1 and 0
Or
x can be any integer above 1
RC & DI Moderator
Joined: 02 Aug 2009
Status:Math and DI Expert
Posts: 11172
Own Kudos [?]: 31897 [0]
Given Kudos: 290
Send PM
Considering the positions on the number line above, which of the follo [#permalink]
Expert Reply
Bunuel wrote:

Considering the positions on the number line above, which of the following could be a value for x?

A. 5/3
B. 3/5
C. -2/5
D. -5/2
E. none

Attachment:
p006-3.gif


lets see the values x can take..



1) \(x^3<x^2.................x^3-x^2<0...............x^2(x-1)<0...................\)
this means \(x<1\) as \(x^2\) cannot be negative...

2) \(x<x^3............. x^3-x>0...........x(x^2-1)>0.........\)...
so both x and x^2-1 will be of the same sign..

a) if x is +ive, \(x^2-1>0...............x^2>1............ x>1... OR ...x<-1.......\) BUT x is +ive so x>1..
But we have seen above x<1.. so this is not possible

b) if x is -ive, \(x^2-1<0...............x^2<1............ x<1... OR ...x>-1.......\) BUT x is -ive so x lies between -1 and 0.....

From above 2 points, x lies between -1 and 0..... so x is -3/5
C
Retired Moderator
Joined: 22 Aug 2013
Posts: 1186
Own Kudos [?]: 2499 [0]
Given Kudos: 459
Location: India
Send PM
Re: Considering the positions on the number line above, which of the follo [#permalink]
We are looking for a number where x < x^3 < x^2 .

This particular question can be easily solved through options.

A) 5/3.. this number is >1, so its square would be lesser than its cube. Eliminated.

B) 3/5.. this number lies between 0 and 1. So with increasing powers, value will keep on decreasing. So its cube will be lesser than the number itself . Eliminated.

C) -2/5 or -0.4. Its cube = -0.064, which is closer to zero hence greater than the number itself. Its square is positive and hence will be greater than both number and its cube. This is the one.

D) -5/2 or -2.5. This number is less than 1, its cube will be lesser than the number, not greater. Eliminated.

Hence C answer
Senior Manager
Senior Manager
Joined: 08 Jun 2015
Posts: 259
Own Kudos [?]: 82 [0]
Given Kudos: 145
Location: India
GMAT 1: 640 Q48 V29
GMAT 2: 700 Q48 V38
GPA: 3.33
Send PM
Re: Considering the positions on the number line above, which of the follo [#permalink]
+1 for option C. It is clear that this combination is possible only for negative numbers. Try out with negative options available. Only option C fits the bill.
User avatar
Non-Human User
Joined: 09 Sep 2013
Posts: 32662
Own Kudos [?]: 821 [0]
Given Kudos: 0
Send PM
Re: Considering the positions on the number line above, which of the follo [#permalink]
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 Club Bot
Re: Considering the positions on the number line above, which of the follo [#permalink]
Moderators:
Math Expert
92900 posts
Senior Moderator - Masters Forum
3137 posts

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