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

It is currently 04 May 2016, 00:02
GMAT Club Tests

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?

  new topic post reply Question banks Downloads My Bookmarks Reviews Important topics  
Author Message
TAGS:

Hide Tags

Intern
Intern
avatar
Joined: 15 Feb 2010
Posts: 11
Followers: 0

Kudos [?]: 9 [0], given: 0

Is 7^7/7^x an integer? [#permalink]

Show Tags

New post 19 Mar 2010, 19:35
3
This post was
BOOKMARKED
00:00
A
B
C
D
E

Difficulty:

  55% (hard)

Question Stats:

53% (01:00) correct 47% (00:50) wrong based on 159 sessions

HideShow timer Statictics

Is \(\frac{7^7}{7^x}\) an integer?

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

(C) 2008 GMAT Club - m04#26

[Reveal] Spoiler:
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
[Reveal] Spoiler: OA
Senior Manager
Senior Manager
User avatar
Joined: 13 Dec 2009
Posts: 263
Followers: 10

Kudos [?]: 161 [0], given: 13

Reviews Badge
Re: Is 7^7/7^x an integer? [#permalink]

Show Tags

New post 20 Mar 2010, 07:53
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: Is 7^7/7^x an integer? [#permalink]

Show Tags

New post 20 Mar 2010, 10:37
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: 320
Followers: 2

Kudos [?]: 26 [0], given: 35

Re: Is 7^7/7^x an integer? [#permalink]

Show Tags

New post 20 Mar 2010, 11:08
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
GMAT Club Legend
GMAT Club Legend
User avatar
Joined: 09 Sep 2013
Posts: 9274
Followers: 455

Kudos [?]: 115 [0], given: 0

Premium Member
Re: Is 7^7/7^x an integer? [#permalink]

Show Tags

New post 26 Aug 2015, 13:34
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 Books | GMAT Club Tests | Best Prices on GMAT Courses | GMAT Mobile App | Math Resources | Verbal Resources

Intern
Intern
avatar
Joined: 20 Apr 2015
Posts: 5
Followers: 0

Kudos [?]: 0 [0], given: 26

Re: Is 7^7/7^x an integer? [#permalink]

Show Tags

New post 07 Oct 2015, 03:41
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.


hii please tell me how do we get just those 3 values for x.
Expert Post
Math Expert
User avatar
Joined: 02 Sep 2009
Posts: 32604
Followers: 5651

Kudos [?]: 68572 [0], given: 9815

Re: Is 7^7/7^x an integer? [#permalink]

Show Tags

New post 07 Oct 2015, 05:35
Expert's post
shreeya wrote:
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.


hii please tell me how do we get just those 3 values for x.


Square \(|x| = x^2\):

\(x^2 = x^4\);

\(x^2 - x^4 = 0\);

\(x^2(1 - x^2) = 0\);

\(x^2(1 - x)(1 + x) = 0\);

\(x = 0\), \(x = 1\), or \(x = -1\).

Hope it's clear.
_________________

New to the Math Forum?
Please read this: All You Need for Quant | PLEASE READ AND FOLLOW: 12 Rules for Posting!!!

Resources:
GMAT Math Book | Triangles | Polygons | Coordinate Geometry | Factorials | Circles | Number Theory | Remainders; 8. Overlapping Sets | PDF of Math Book; 10. Remainders | GMAT Prep Software Analysis | SEVEN SAMURAI OF 2012 (BEST DISCUSSIONS) | Tricky questions from previous years.

Collection of Questions:
PS: 1. Tough and Tricky questions; 2. Hard questions; 3. Hard questions part 2; 4. Standard deviation; 5. Tough Problem Solving Questions With Solutions; 6. Probability and Combinations Questions With Solutions; 7 Tough and tricky exponents and roots questions; 8 12 Easy Pieces (or not?); 9 Bakers' Dozen; 10 Algebra set. ,11 Mixed Questions, 12 Fresh Meat

DS: 1. DS tough questions; 2. DS tough questions part 2; 3. DS tough questions part 3; 4. DS Standard deviation; 5. Inequalities; 6. 700+ GMAT Data Sufficiency Questions With Explanations; 7 Tough and tricky exponents and roots questions; 8 The Discreet Charm of the DS; 9 Devil's Dozen!!!; 10 Number Properties set., 11 New DS set.


What are GMAT Club Tests?
Extra-hard Quant Tests with Brilliant Analytics

Intern
Intern
avatar
Joined: 20 Apr 2015
Posts: 5
Followers: 0

Kudos [?]: 0 [0], given: 26

Re: Is 7^7/7^x an integer? [#permalink]

Show Tags

New post 07 Oct 2015, 07:29
yes .. :) thanks
Re: Is 7^7/7^x an integer?   [#permalink] 07 Oct 2015, 07:29
    Similar topics Author Replies Last post
Similar
Topics:
Experts publish their posts in the topic If a is an integer, is b an integer? Bunuel 8 03 Apr 2015, 04:47
8 Experts publish their posts in the topic Is a an integer? JusTLucK04 5 31 Oct 2014, 13:35
4 Experts publish their posts in the topic If x is an integer, is y an integer? Bunuel 7 28 Feb 2014, 04:01
1 Experts publish their posts in the topic If x is an integer, is y an integer? boomtangboy 14 28 Apr 2012, 21:25
1 Experts publish their posts in the topic If p is an integer, is q an integer? enigma123 2 11 Feb 2012, 18:41
Display posts from previous: Sort by

Is 7^7/7^x an integer?

  new topic post reply Question banks Downloads My Bookmarks Reviews Important topics  


GMAT Club MBA Forum Home| About| 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®.