Find all School-related info fast with the new School-Specific MBA Forum

It is currently 22 Jul 2014, 13:53

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.

Events & Promotions

Events & Promotions in June
Open Detailed Calendar

Is 7^7/7^x an integer? (1) 0\leq{x}\leq{7} (2) |x|=x^2 (C)

  Question banks Downloads My Bookmarks Reviews Important topics  
Author Message
TAGS:
Intern
Intern
avatar
Joined: 15 Feb 2010
Posts: 11
Followers: 0

Kudos [?]: 3 [0], given: 0

Is 7^7/7^x an integer? (1) 0\leq{x}\leq{7} (2) |x|=x^2 (C) [#permalink] New post 19 Mar 2010, 18:35
00:00
A
B
C
D
E

Difficulty:

(N/A)

Question Stats:

0% (00:00) correct 0% (00:00) wrong based on 0 sessions
Is \frac{7^7}{7^x} an integer?

(1) 0\leq{x}\leq{7}
(2) |x|=x^2

(C) 2008 GMAT Club - m04#26

Statement (1) ALONE is sufficient, but Statement (2) ALONE is not sufficient
Statement (2) ALONE is sufficient, but Statement (1) ALONE is not sufficient
BOTH statements TOGETHER are sufficient, but NEITHER statement ALONE is sufficient
EACH statement ALONE is sufficient
Statements (1) and (2) TOGETHER are NOT sufficient
, so as long as is an integer and , the expression is an integer.

Statement (1) by itself is insufficient. S1 says that x can be between 0 and 7, so it can be an integer or any fraction.

Statement (2) by itself is sufficient. S2 implies that x is one of (-1, 0, 1). .

The correct answer is B.


WHY CAN THIS BE AN INTEGER OR ANY FRACTION, ISN'T IT ANY INTEGER ALL THE WAY. BECAUSE THE LEAST WHEN X= 7 IS 1 AND X=0 IS 7 * 7*7*7*7*7*7
Kaplan GMAT Prep Discount CodesKnewton GMAT Discount CodesVeritas Prep GMAT Discount Codes
Senior Manager
Senior Manager
User avatar
Joined: 13 Dec 2009
Posts: 264
Followers: 10

Kudos [?]: 99 [0], given: 13

GMAT Tests User Reviews Badge
Re: need explanation please! [#permalink] New post 20 Mar 2010, 06:53
aramjung wrote:
Is \frac{7^7}{7^x} an integer?

(1) 0\leq{x}\leq{7}
(2) |x|=x^2


stmt1: x can be fraction between 0 to 7 so insuff.
stmt2: |x| = x^2
-x = x^2 => x(x+1) = 0 => x = 0 or x = -1
or
x = x^2 => x(x-1) = 0 => x = 0 or x = 1
in any of the three cases 0, 1 , -1 it is going ot be an integer to sufficient.
Hence, B is the answer.
it cannot be fraction all the way, take for example x = 1/2 it is between 0 to 7 but 7^7/7^1/2 is not an integer

_________________

My debrief: done-and-dusted-730-q49-v40

Intern
Intern
avatar
Joined: 19 Mar 2010
Posts: 11
Location: San Diego, CA
Schools: UCLA Anderson
Followers: 0

Kudos [?]: 1 [0], given: 3

Re: need explanation please! [#permalink] New post 20 Mar 2010, 09:37
S1. It is not specified that x is an integer. Using a value such as x=3.5 in the original function will result in a non-integer. Insufficient.
S2. x can only be equal to -1, 0. or 1. Using these values in the original function will always result in an integer. Sufficient.

Answer is B
Senior Manager
Senior Manager
User avatar
Status: Can't give up
Joined: 20 Dec 2009
Posts: 321
Followers: 2

Kudos [?]: 24 [0], given: 35

GMAT Tests User
Re: need explanation please! [#permalink] New post 20 Mar 2010, 10:08
1.) x can be any value from 0-7 including decimals. so this is Insuff

2.) using B x= -1, 0, 1, -2, 2.....x is an integer.

Hence B
Re: need explanation please!   [#permalink] 20 Mar 2010, 10:08
    Similar topics Author Replies Last post
Similar
Topics:
Experts publish their posts in the topic Let [x]=(x^2+1)/2 and (y)=3y/2, for all integers x and y Jakevmi80 1 23 Mar 2012, 13:00
what is the value of |x| (1) x=-|x| (2)x^2=4 sacmanitin 6 12 Oct 2009, 23:45
If x is an integer, then x(x + 2)(x + 3) is a) odd rdg 6 09 Mar 2007, 09:53
What is the value of the integer x? (1) x(x + 2) = 15 (2) (x jlui4477 3 15 Apr 2006, 11:40
What is the value of the integer x? (1) x(x + 2) = 15 (2) (x joemama142000 3 13 Feb 2006, 20:43
Display posts from previous: Sort by

Is 7^7/7^x an integer? (1) 0\leq{x}\leq{7} (2) |x|=x^2 (C)

  Question banks Downloads My Bookmarks Reviews Important topics  


GMAT Club MBA Forum Home| About| Privacy Policy| Terms and Conditions| GMAT Club Rules| Contact| Sitemap

Powered by phpBB © phpBB Group and phpBB SEO

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®.