Last visit was: 23 Apr 2026, 04:33 It is currently 23 Apr 2026, 04:33
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
User avatar
Nevernevergiveup
User avatar
Retired Moderator
Joined: 18 Sep 2014
Last visit: 20 Aug 2023
Posts: 998
Own Kudos:
3,080
 [25]
Given Kudos: 79
Location: India
Products:
Posts: 998
Kudos: 3,080
 [25]
4
Kudos
Add Kudos
21
Bookmarks
Bookmark this Post
User avatar
0ld
Joined: 24 Aug 2016
Last visit: 09 Apr 2017
Posts: 48
Own Kudos:
82
 [4]
Given Kudos: 24
Location: India
WE:Information Technology (Computer Software)
Posts: 48
Kudos: 82
 [4]
2
Kudos
Add Kudos
2
Bookmarks
Bookmark this Post
User avatar
rohit8865
Joined: 05 Mar 2015
Last visit: 19 Apr 2026
Posts: 815
Own Kudos:
1,008
 [1]
Given Kudos: 45
Products:
Posts: 815
Kudos: 1,008
 [1]
1
Kudos
Add Kudos
Bookmarks
Bookmark this Post
User avatar
KrishnakumarKA1
Joined: 05 Jan 2017
Last visit: 13 Oct 2020
Posts: 398
Own Kudos:
Given Kudos: 15
Location: India
Posts: 398
Kudos: 314
Kudos
Add Kudos
Bookmarks
Bookmark this Post
SUPER SET
The value of k will be a real number.

TRANSLATION
In order to find the value, we need:
Exact value of k.
Any equation to solve for k.
Any characteristics of k.

STATEMENT ANALYSIS
St 1: k^4=1/625
k^4-1/625 = 0
k^4- ⅕^4 = 0
(k^2+1/25)(k +⅕)(k-⅕) = 0
Therefore k = ⅕, -⅕
INSUFFICIENT. Hence option a and d eliminated.

St 2: k^3<k^2, holds for infinite values of k. INSUFFICIENT. Hence option b eliminated.

St 1 & St 2: From St 1, we got k = ⅕, -⅕. Putting these values in the equation from St 2, we get k = -⅕ as well as ⅕ holds true for the equation. HEnce INSUFFICIENT. Option C eliminated.

Hence option E
User avatar
Gladiator59
Joined: 16 Sep 2016
Last visit: 18 Mar 2026
Posts: 841
Own Kudos:
Given Kudos: 271
Status:It always seems impossible until it's done.
GMAT 1: 740 Q50 V40
GMAT 2: 770 Q51 V42
Products:
GMAT 2: 770 Q51 V42
Posts: 841
Kudos: 2,716
Kudos
Add Kudos
Bookmarks
Bookmark this Post
SonalSinha803
What is the value of k ?

1. k ^ 4 = 1/625

2. k ^ 3 < k ^ 2

Sent from my Lenovo K53a48 using GMAT Club Forum mobile app

IMO E.

Statement 1) \(k^4 = 1/625\)
-> \(k^2 = 1/25\) ( taking square root and neglecting the negative value)
-> \(k = +- 1/5\) ( taking sq root)

Not sufficient.

Statement 2) \(k^3 < k^2\)

This could be true in two cases - 1) k is negative. So k cube is negative while k square is positive.
2) k is positive and between 0 and 1. Increasing powers of k become smaller.
Not sufficient.

(1) and (2) together are also insufficient.

Hence E.

Please give kudos if you liked my explanation...
User avatar
Gladiator59
Joined: 16 Sep 2016
Last visit: 18 Mar 2026
Posts: 841
Own Kudos:
2,716
 [1]
Given Kudos: 271
Status:It always seems impossible until it's done.
GMAT 1: 740 Q50 V40
GMAT 2: 770 Q51 V42
Products:
GMAT 2: 770 Q51 V42
Posts: 841
Kudos: 2,716
 [1]
1
Kudos
Add Kudos
Bookmarks
Bookmark this Post
PraveenChahal
.
Combining the two equations is still insufficient as..

+1/5 and -1/5 could both be k.
We need to zero down to one possibility.

Hope that solved your question.

Kindly give Kudos if you liked my post...
User avatar
SonalSinha803
Joined: 14 Feb 2018
Last visit: 18 Feb 2019
Posts: 303
Own Kudos:
Given Kudos: 29
Posts: 303
Kudos: 324
Kudos
Add Kudos
Bookmarks
Bookmark this Post
Hi,

What I did with the second option is

k^3 - k^2 = k^2(k - 1) < 0

Thus, k < 0 or k < 1

Where am I wrong...please do explain.

Sent from my Lenovo K53a48 using GMAT Club Forum mobile app
User avatar
Gladiator59
Joined: 16 Sep 2016
Last visit: 18 Mar 2026
Posts: 841
Own Kudos:
Given Kudos: 271
Status:It always seems impossible until it's done.
GMAT 1: 740 Q50 V40
GMAT 2: 770 Q51 V42
Products:
GMAT 2: 770 Q51 V42
Posts: 841
Kudos: 2,716
Kudos
Add Kudos
Bookmarks
Bookmark this Post
SonalSinha803
Hi,

What I did with the second option is

k^3 - k^2 = k^2(k - 1) < 0

Thus, k < 0 or k < 1

Where am I wrong...please do explain.

Sent from my Lenovo K53a48 using GMAT Club Forum mobile app

SonalSinha803
Your result is correct. What do you infer from that? K could have both values of +1/5 and -1/5 ( also considering the info from statement 1) so both statements are not sufficient.

Does that make sense?
User avatar
GMATBusters
User avatar
GMAT Tutor
Joined: 27 Oct 2017
Last visit: 23 Apr 2026
Posts: 1,921
Own Kudos:
Given Kudos: 241
WE:General Management (Education)
Expert
Expert reply
Posts: 1,921
Kudos: 6,855
Kudos
Add Kudos
Bookmarks
Bookmark this Post
hi
Your interpretation should be only interpretation will be k<1. it will automatically cover x<0 :cool:
So it will cover both 1/5 and -1/5 ( as both are less than 1).
hence it is not sufficient.

Hence E.


SonalSinha803
Hi,

What I did with the second option is

k^3 - k^2 = k^2(k - 1) < 0

Thus, k < 0 or k < 1

Where am I wrong...please do explain.

Sent from my Lenovo K53a48 using GMAT Club Forum mobile app
User avatar
SonalSinha803
Joined: 14 Feb 2018
Last visit: 18 Feb 2019
Posts: 303
Own Kudos:
Given Kudos: 29
Posts: 303
Kudos: 324
Kudos
Add Kudos
Bookmarks
Bookmark this Post
Thankyou everyone....I realised I made a silly mistake.

Thankyou for the clarity [GRINNING FACE WITH SMILING EYES]

Sent from my Lenovo K53a48 using GMAT Club Forum mobile app
User avatar
bumpbot
User avatar
Non-Human User
Joined: 09 Sep 2013
Last visit: 04 Jan 2021
Posts: 38,956
Own Kudos:
Posts: 38,956
Kudos: 1,117
Kudos
Add Kudos
Bookmarks
Bookmark this Post
Automated notice from GMAT Club BumpBot:

A member just gave Kudos to this thread, showing it’s still useful. I’ve bumped it to the top so more people can benefit. Feel free to add your own questions or solutions.

This post was generated automatically.
Moderators:
Math Expert
109775 posts
498 posts
212 posts