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

 It is currently 18 Aug 2018, 05:21

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

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

If x^4 > x^5 > x^3, which of the following could be the value of x?

Author Message
TAGS:

Hide Tags

Math Expert
Joined: 02 Sep 2009
Posts: 47981
If x^4 > x^5 > x^3, which of the following could be the value of x?  [#permalink]

Show Tags

23 Feb 2016, 03:05
1
2
00:00

Difficulty:

15% (low)

Question Stats:

82% (00:55) correct 18% (00:48) wrong based on 164 sessions

HideShow timer Statistics

If x^4 > x^5 > x^3, which of the following could be the value of x?

A. -3
B. -2
C. -2/3
D. 2/3
E. 3

Kudos for correct solution.

_________________
Math Expert
Joined: 02 Aug 2009
Posts: 6549
If x^4 > x^5 > x^3, which of the following could be the value of x?  [#permalink]

Show Tags

23 Feb 2016, 08:28
2
1
Bunuel wrote:
If x^4 > x^5 > x^3, which of the following could be the value of x?

A. -3
B. -2
C. -2/3
D. 2/3
E. 3

Kudos for correct solution.

Hi,
this Q tests us on our concepts on Number properties..
x^4 > x^5 > x^3
1)here we have even power of a variable and it is more than both a bigger odd power and smaller odd power..
It can be possible only if the base is negative so x is -ive..
2) Now if x is negative, a higher power means a smaller number, if x<-1..
and a higher power results in a bigger number if 0>x>-1

combined we know that x is a negative number greater than -1..

only -2/3 is in the choices..
ans C

SUBSTITUTE
Ofcourse we can substitute each value given in choice and find answer

_________________

1) Absolute modulus : http://gmatclub.com/forum/absolute-modulus-a-better-understanding-210849.html#p1622372
2)Combination of similar and dissimilar things : http://gmatclub.com/forum/topic215915.html
3) effects of arithmetic operations : https://gmatclub.com/forum/effects-of-arithmetic-operations-on-fractions-269413.html

GMAT online Tutor

Current Student
Status: Persevere
Joined: 09 Jan 2016
Posts: 122
Location: Hong Kong
GMAT 1: 750 Q50 V41
GPA: 3.52
If x^4 > x^5 > x^3, which of the following could be the value of x?  [#permalink]

Show Tags

23 Feb 2016, 09:47
Bunuel wrote:
If x^4 > x^5 > x^3, which of the following could be the value of x?

A. -3
B. -2
C. -2/3
D. 2/3
E. 3

Kudos for correct solution.

Let's break this question down into two parts. I: $$x^4 > x^5$$ and II: $$x^5 > x^3$$
Consider Part I:
$$x^4 > x^5$$
For this to be true, either $$x$$ is negative or it is a fraction less than 1

Consider Part II:
$$x^5 > x^3$$
If $$x$$ is negative, then for this to be true, $$x$$ has to be greater than -1.
If $$x$$ is a fraction less than 1, then for this part to be true, $$x$$ must also be negative.

In either case, $$x$$ can be represented by the inequality $$0>x>-1$$.
The only option that satisfies this condition is C (-2/3)
Director
Joined: 05 Mar 2015
Posts: 985
Re: If x^4 > x^5 > x^3, which of the following could be the value of x?  [#permalink]

Show Tags

01 Apr 2016, 18:37
Bunuel wrote:
If x^4 > x^5 > x^3, which of the following could be the value of x?

A. -3
B. -2
C. -2/3
D. 2/3
E. 3

Kudos for correct solution.

consider all three cases saperatly
a> x^4>x^3
b> x^5>x^3
c>x^4>x^5

a> x^4-x^3>0------>x^2-x>0------->x>1 or x<0
b> x^3-x>0---------->x>1 or -1<x<0
c> x^4-x^5>0-------> x^5-x^4<0-------->x-1<0------>x<1

intersection point of all three ranges are -1<x<0
only option C satisfies the criteria
So ans C.
Target Test Prep Representative
Affiliations: Target Test Prep
Joined: 04 Mar 2011
Posts: 2727
Re: If x^4 > x^5 > x^3, which of the following could be the value of x?  [#permalink]

Show Tags

29 Jan 2018, 10:39
Bunuel wrote:
If x^4 > x^5 > x^3, which of the following could be the value of x?

A. -3
B. -2
C. -2/3
D. 2/3
E. 3

We are given that x^4 > x^5 > x^3.

Since x^4 is greater than x^5, we see that x cannot be a positive integer.

Since x^5 is greater than x^3, we see that x cannot be a negative integer or a positive proper fraction.

Thus, x must be -2/3.

_________________

Jeffery Miller

GMAT Quant Self-Study Course
500+ lessons 3000+ practice problems 800+ HD solutions

Re: If x^4 > x^5 > x^3, which of the following could be the value of x? &nbs [#permalink] 29 Jan 2018, 10:39
Display posts from previous: Sort by

Events & Promotions

 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®.