It is currently 24 Jun 2017, 11:54

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

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

Events & Promotions

Events & Promotions in June
Open Detailed Calendar

What is the greatest prime factor of 2^100 - 2^96? A. 2

 post reply Question banks Downloads My Bookmarks Reviews Important topics
Author Message
SVP
Joined: 14 Dec 2004
Posts: 1689
What is the greatest prime factor of 2^100 - 2^96? A. 2  [#permalink]

Show Tags

31 Dec 2005, 05:23
00:00

Difficulty:

(N/A)

Question Stats:

0% (00:00) correct 0% (00:00) wrong based on 0 sessions

HideShow timer Statistics

This topic is locked. If you want to discuss this question please re-post it in the respective forum.

What is the greatest prime factor of 2^100 - 2^96?

A. 2
B. 3
C. 5
D. 7
E. 11
Director
Joined: 17 Dec 2005
Posts: 547
Location: Germany

Show Tags

31 Dec 2005, 05:33
2^100 - 2^96=

(2^4)*(2^96) - 2^96= 2^96(2^4 - 1)

The greatest prime factor of 2^96 is 2

2^4 - 1= 15, so the prime factor are 3 and 5

It is C, I think
GMAT Club Legend
Joined: 07 Jul 2004
Posts: 5043
Location: Singapore

Show Tags

09 Jan 2006, 01:33
2^100 - 2^96 = 2^96 (2^4 - 1) = 15 (2^96) = 3*5*2^96

Ans C
CEO
Joined: 20 Nov 2005
Posts: 2894
Schools: Completed at SAID BUSINESS SCHOOL, OXFORD - Class of 2008

Show Tags

09 Jan 2006, 02:27
C

2^100 - 2^96= 2^96(2^4 - 1) = (2^96) * 15

So prime factors are 2,3,5
_________________

SAID BUSINESS SCHOOL, OXFORD - MBA CLASS OF 2008

VP
Joined: 20 Sep 2005
Posts: 1017

Show Tags

10 Jan 2006, 15:13
5 in 5 seconds...hope that I don't get such questions in the actual GMAT..which would probably mean that I screwed up big time....
10 Jan 2006, 15:13
Display posts from previous: Sort by

What is the greatest prime factor of 2^100 - 2^96? A. 2

 post reply Question banks Downloads My Bookmarks Reviews Important topics

 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®.