NEW HERE? LEARN MORE
closeclose
Last visit was: 25 Apr 2024, 16:20 It is currently 25 Apr 2024, 16:20
Decision Tracker
My Rewards
New posts
New comers' posts

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

For all n>0,7^6n-6^6n is divisible by....?? a)13

User avatar
shubhangi
Manager
Manager
Joined: 30 Aug 2003
Posts: 183
Own Kudos [?]: 157 [0]
Given Kudos: 0
Location: dallas , tx
Send PM
For all n>0,7^6n-6^6n is divisible by....?? a)13 [#permalink] New post   19 Dec 2003, 15:14
00:00
A
B
C
D
E

Difficulty:

(N/A)

Question Stats:

0% (00:00) correct 0% (00:00) wrong based on 0 sessions
Hide Show timer Statistics
For all n>0,7^6n-6^6n is divisible by....??

a)13
b)127
c)559
d)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
Paul
CEO
CEO
Joined: 15 Dec 2003
Posts: 2709
Own Kudos [?]: 1538 [0]
Given Kudos: 0
Send PM
Re: For all n>0,7^6n-6^6n is divisible by....?? a)13 [#permalink] New post   19 Dec 2003, 17:11
I believe A is the answer

Let's take 6n=2 or in other words, n=1/3
The difference between 7^2 and 6^2 = 49-36 = 13
Therefore, as we increase n, the difference between the 2 terms will increase by a base of 13 exponent any number. Thus, the answer is that the solution is divisible by 13
User avatar
Praetorian
CEO
CEO
Joined: 15 Aug 2003
Posts: 2876
Own Kudos [?]: 1649 [0]
Given Kudos: 781
Send PM
Re: For all n>0,7^6n-6^6n is divisible by....?? a)13 [#permalink] New post   19 Dec 2003, 19:14
shubhangi wrote:
For all n>0,7^6n-6^6n is divisible by....??

a)13
b)127
c)559
d)none



factor 13 = 13*1

numerator does not have a 13 at all...out it goes

factor 127=> i think its prime. again..no luck

factor 559 => again prime

i think its just D
User avatar
pitts20042006
Manager
Manager
Joined: 12 Oct 2003
Posts: 175
Own Kudos [?]: 18 [0]
Given Kudos: 0
Location: USA
Send PM
Re: For all n>0,7^6n-6^6n is divisible by....?? a)13 [#permalink] New post   20 Dec 2003, 11:10
Why would you want to factor 13? Or am I just missing the point here?

I also did not follow ..
Quote:
If n=1, 7^6n-6^6n=1^6=1 so d)


Also, in the question stem, should n be associated with 6 or with 7?

Paul wrote:
Quote:
Let's take 6n=2 or in other words, n=1/3
The difference between 7^2 and 6^2 = 49-36 = 13
Therefore, as we increase n, the difference between the 2 terms will increase by a base of 13 exponent any number


What if n = 1/6??? the difference comes up to 1 which is not divisible by 13.
User avatar
shubhangi
Manager
Manager
Joined: 30 Aug 2003
Posts: 183
Own Kudos [?]: 157 [0]
Given Kudos: 0
Location: dallas , tx
Send PM
Re: For all n>0,7^6n-6^6n is divisible by....?? a)13 [#permalink] New post   20 Dec 2003, 16:12
Well the correct answer is D .. but i didnt understand the official approach. Praet's way was quite logical and easy .
Thanks
User avatar
AkamaiBrah
GMAT Instructor
Joined: 07 Jul 2003
Posts: 392
Own Kudos [?]: 468 [0]
Given Kudos: 0
Location: New York NY 10024
Concentration: Finance
Schools:Haas, MFE; Anderson, MBA; USC, MSEE
Send PM
Re: For all n>0,7^6n-6^6n is divisible by....?? a)13 [#permalink] New post   20 Dec 2003, 17:35
BG wrote:
If n=1, 7^6n-6^6n=1^6=1 so d)


I'm sorry, but x^z - y^z is NOT equal to (x-y)^z.
User avatar
mantha
Manager
Manager
Joined: 11 Oct 2003
Posts: 57
Own Kudos [?]: 3 [0]
Given Kudos: 0
Location: USA
Send PM
Re: For all n>0,7^6n-6^6n is divisible by....?? a)13 [#permalink] New post   20 Dec 2003, 18:22
Let n = 1/6 then 7-6 =1. It will be an interesting problem if n was an integer > 0.
User avatar
stoolfi
Manager
Manager
Joined: 28 Oct 2003
Posts: 246
Own Kudos [?]: 260 [0]
Given Kudos: 0
Location: 55405
Send PM
Re: For all n>0,7^6n-6^6n is divisible by....?? a)13 [#permalink] New post   20 Dec 2003, 22:40
mantha is exactly right-- why not just choose 1/6 for n, plug, and be done?



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!
GMAT Club Bot
gmatclubot
Re: For all n>0,7^6n-6^6n is divisible by....?? a)13 [#permalink]
20 Dec 2003, 22:40
Moderators:
Bunuel
Math Expert
92915 posts
yashikaaggarwal
Senior Moderator - Masters Forum
3137 posts

Powered by phpBB © phpBB Group | Emoji artwork provided by EmojiOne
Main navigation
GMAT Resources
Partners
MBA Resources
www.gmac.com|www.mba.com | | GMAT Club Rules | Terms and Conditions