BREAKING: Target Test Prep releases Brand New 2026 On Demand GMAT prep course

Redeem

What is the greatest prime factor of

This topic has expert replies
Post new topic Post Reply
Previous Topic Next Topic
Source: — Problem Solving |
Senior | Next Rank: 100 Posts
Posts: 39
Joined: Mon Feb 08, 2010 12:41 pm

by Lookingfor700GMAT » Wed Mar 10, 2010 9:48 am
To be clear the stimulus is

4^17-2^28
Top
GMAT Instructor
Posts: 1578
Joined: Thu May 28, 2009 8:02 am
Thanked: 128 times
Followed by:34 members
GMAT Score:760

by Osirus@VeritasPrep » Wed Mar 10, 2010 10:05 am
rewrite 4^17 as (2^2)^17

This equals 2^34

Now you have to factor 2^34 - 2^28

this equals 2^28 (2^6 - 1)

this equals 2^28 (64-1)

This equals 2^28 (63)

63 broken into prime factors is 3^2 * 7

Therefore, the greatest prime factor is 7
https://www.beatthegmat.com/the-retake-o ... 51414.html

Brandon Dorsey
GMAT Instructor
Veritas Prep

Buy any Veritas Prep book(s) and receive access to 5 Practice Cats for free! Learn More.
Top
Senior | Next Rank: 100 Posts
Posts: 39
Joined: Mon Feb 08, 2010 12:41 pm

by Lookingfor700GMAT » Wed Mar 10, 2010 10:48 am
Awesome stuff. Thanks!
Top
Senior | Next Rank: 100 Posts
Posts: 39
Joined: Mon Feb 08, 2010 12:41 pm

by Lookingfor700GMAT » Wed Mar 10, 2010 11:07 am
Actually can you explain these steps again please

rewrite 4^17 as (2^2)^17

This equals 2^34

Now you have to factor 2^34 - 2^28

this equals 2^28 (2^6 - 1)
Top
Post new topic Post Reply
• Page 1 of 1