Last visit was: 22 Apr 2026, 19:54 It is currently 22 Apr 2026, 19:54
Home
Messages
Tests
Schools
Events
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.
Go to My Error Log Learn more
Close
Request Expert Reply
Confirm Cancel
User avatar
apoorvasrivastva
User avatar
Joined: 29 Jul 2009
Last visit: 11 Oct 2021
Posts: 44
Own Kudos:
364
Given Kudos: 24
Posts: 44
Kudos: 364
Number Properties!!! 13 Jan 2010, 13:42
Kudos
Add Kudos
Bookmarks
Bookmark this Post
00:00
Start Timer
Pause Timer
Resume Timer
Show Answer
Hide
Show
History
N
Be sure to select an answer first to save it in the Error Log before revealing the correct answer (OA)!

Difficulty:

(N/A)

Question Stats:

0% (00:00) correct 100% (00:47) wrong based on 3 sessions

History

Date
Time
Result
Not Attempted Yet
If k^(xy)=1, where k is not zero, which of the following must be true?
I. k=1
II. x=0
III. y=0
(A) I only
(B) II only
(C) III only
(D) I and II
(E) None



Archived Topic
Hi there,
This topic has been closed and archived due to inactivity or violation of community quality standards. No more replies are possible here.
Where to now? Join ongoing discussions on thousands of quality questions in our Problem Solving (PS) Forum
Still interested in this question? Check out the "Best Topics" block below for a better discussion on this exact question, as well as several more related questions.
Thank you for understanding, and happy exploring!
User avatar
BarneyStinson
User avatar
Joined: 21 Jul 2009
Last visit: 24 Sep 2010
Posts: 217
Own Kudos:
508
Given Kudos: 22
Concentration: World Domination, Finance, Political Corporatization, Marketing, Strategy
Schools:LBS, INSEAD, IMD, ISB - Anything with just 1 yr program.
Posts: 217
Kudos: 508
Number Properties!!! 13 Jan 2010, 14:57
Kudos
Add Kudos
Bookmarks
Bookmark this Post
apoorvasrivastva
If k^(xy)=1, where k is not zero, which of the following must be true?
I. k=1
II. x=0
III. y=0
(A) I only
(B) II only
(C) III only
(D) I and II
(E) None
Show more

My take, it is E.

K^(xy) = 1 = K^0, anything to the power of 0 is always 1.
Hence, xy = 0, so either x = 0 or y = 0. Among the given options, there is nothing that says either II or III, so we cannot ascertain specifically so, option E is the answer.
User avatar
cipher
User avatar
Joined: 25 Jun 2009
Last visit: 04 Aug 2013
Posts: 130
Own Kudos:
349
Given Kudos: 6
Posts: 130
Kudos: 349
Number Properties!!! 13 Jan 2010, 14:59
Kudos
Add Kudos
Bookmarks
Bookmark this Post
apoorvasrivastva
If k^(xy)=1, where k is not zero, which of the following must be true?
I. k=1
II. x=0
III. y=0
(A) I only
(B) II only
(C) III only
(D) I and II
(E) None
Show more


IMO,

It should be all of them.

Any equation of the form K^Z can only be 1 if
a. Z =0
b K=1

In this case all the options (1,2 and 3) seems valid. whats the OA and source of this question.

Cheers,
User avatar
cipher
User avatar
Joined: 25 Jun 2009
Last visit: 04 Aug 2013
Posts: 130
Own Kudos:
349
Given Kudos: 6
Posts: 130
Kudos: 349
Number Properties!!! 13 Jan 2010, 15:01
Kudos
Add Kudos
Bookmarks
Bookmark this Post
BarneyStinson
apoorvasrivastva
If k^(xy)=1, where k is not zero, which of the following must be true?
I. k=1
II. x=0
III. y=0
(A) I only
(B) II only
(C) III only
(D) I and II
(E) None

My take, it is E.

K^(xy) = 1 = K^0, anything to the power of 0 is always 1.
Hence, xy = 0, so either x = 0 or y = 0. Among the given options, there is nothing that says either II or III, so we cannot ascertain specifically so, option E is the answer.
Show more

Option 1 is also valid because 1 raised to the power anything (0, -1 ,8 etc ) will also be 1
User avatar
GoBruin
User avatar
Current Student
Joined: 05 Aug 2008
Last visit: 26 Jan 2017
Posts: 1,262
Own Kudos:
175
Given Kudos: 20
Concentration: Management Consulting
Schools: Ross 2012
WE 1: 5 Years at Fortune 50 Company in Manufacturing
Posts: 1,262
Kudos: 175
Number Properties!!! 13 Jan 2010, 15:40
Kudos
Add Kudos
Bookmarks
Bookmark this Post
MUST be true. I think that's the case, must be true changes the dynamics of the question. I vote E
User avatar
ichha148
User avatar
Joined: 16 Apr 2009
Last visit: 23 Feb 2023
Posts: 135
Own Kudos:
491
Given Kudos: 14
Posts: 135
Kudos: 491
Number Properties!!! 13 Jan 2010, 18:02
Kudos
Add Kudos
Bookmarks
Bookmark this Post
I will go with E as well
I think D should say I or II
User avatar
MrEasy
User avatar
Joined: 02 Jan 2010
Last visit: 12 Feb 2011
Posts: 9
Own Kudos:
45
Given Kudos: 1
Posts: 9
Kudos: 45
Number Properties!!! 13 Jan 2010, 19:06
Kudos
Add Kudos
Bookmarks
Bookmark this Post
Process of elimination. Since we know any \(n^ 0\)=1 therefore either x or y is 0 (it could be one or both). I would go with E



Archived Topic
Hi there,
This topic has been closed and archived due to inactivity or violation of community quality standards. No more replies are possible here.
Where to now? Join ongoing discussions on thousands of quality questions in our Problem Solving (PS) Forum
Still interested in this question? Check out the "Best Topics" block above for a better discussion on this exact question, as well as several more related questions.
Thank you for understanding, and happy exploring!
Moderator:
Bunuel
Math Expert
109754 posts