Target Test Prep's 2024 GMAT Focus Edition prep is discounted for the BTG community!

Redeem
Target Test Prep
5-Day Free Trial
5-day free, full-access trial TTP

Available with Beat the GMAT members only code

MORE DETAILS
Target Test Prep
Magoosh
Magoosh
Study with Magoosh GMAT prep

Available with Beat the GMAT members only code

MORE DETAILS
Magoosh

GMATPrep GCF and LCM

This topic has expert replies
Post new topic Post Reply
Previous Topic Next Topic
Master | Next Rank: 500 Posts
Posts: 158
Joined: Mon Dec 03, 2007 8:32 am
Thanked: 7 times

GMATPrep GCF and LCM

by StarDust845 » Sat Jan 26, 2008 5:29 pm
If n and t are positive integers, what is the greatest prime factor of nt?

1) The greatest common factor of n and t is 5.
2) The least common multiple of n and t is 105.
Top
Master | Next Rank: 500 Posts
Posts: 128
Joined: Sat Nov 17, 2007 11:59 am
Thanked: 1 times

by cris » Sat Jan 26, 2008 7:13 pm
I think is B. If I am corect I will explain :D
Top
Junior | Next Rank: 30 Posts
Posts: 28
Joined: Wed Jan 16, 2008 9:10 pm

by malnv » Sat Jan 26, 2008 10:18 pm
Its C.

Number is LCM * GCF
prime factors for 105 *5 - 2,5,7

where 7 is greatest PF
Top
Master | Next Rank: 500 Posts
Posts: 195
Joined: Sun Oct 21, 2007 4:33 am
Thanked: 10 times

by sankruth » Sun Jan 27, 2008 12:28 am
IMO the answer is B.

LCM will have all the unique prime factors of both numbers n & t, which will include the greatest prime factor.
Top
Junior | Next Rank: 30 Posts
Posts: 28
Joined: Wed Jan 16, 2008 9:10 pm

by malnv » Sun Jan 27, 2008 12:43 am
You are right. LCM = product of highest power of ALL prime factors.
- B is SUFF
Top
Master | Next Rank: 500 Posts
Posts: 158
Joined: Mon Dec 03, 2007 8:32 am
Thanked: 7 times

by StarDust845 » Sun Jan 27, 2008 8:38 am
OA is B. I got it wrong though.
Top
Post new topic Post Reply
• Page 1 of 1