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

Redeem

Tough Number Properties question ! Need help

This topic has expert replies
Post new topic Post Reply
Previous Topic Next Topic
Newbie | Next Rank: 10 Posts
Posts: 9
Joined: Sat Aug 06, 2011 8:56 am

Tough Number Properties question ! Need help

by waggrave » Mon Aug 15, 2011 8:52 am
Hello,

I found this question in OG12, and I'm not really satisfied with the explanation given.
Could anyone help me to understand it ?

Thanks a lot...

A school administrator will assign each student in
a group of n students to one of m classrooms. If
3 < m < 13 < n, is it possible to assign each of the
n students to one of the m classrooms so that each
classroom has the same number of students assigned
to it?
(1) It is possible to assign each of 3n students to
one of m classrooms so that each classroom
has the same number of students assigned to it.
(2) It is possible to assign each of 13n students to
one of m classrooms so that each classroom
has the same number of students assigned to it.
Top
Source: — Data Sufficiency |
User avatar
Master | Next Rank: 500 Posts
Posts: 312
Joined: Tue Aug 02, 2011 3:16 pm
Location: New York City
Thanked: 130 times
Followed by:33 members
GMAT Score:780

by gmatboost » Mon Aug 15, 2011 9:50 am
Translation of question:
Is n evenly divisible by m?
(Or, if you prefer: Is m a factor of n?)


Statement 1: 3n is divisible by m / m is a factor of 3n.
This does NOT necessarily mean that m is a factor of n, since the 3 in 3n could be part of m.
For example, m = 6 (contains 3), n = 20 (does not contain 3).

Statement 2: 13n is divisible by m / m is a factor of 13n.
This DOES necessarily mean that m is a factor of n, since m<13 and therefore does not contain 13 as a factor.

Answer is B.
Greg Michnikov, Founder of GMAT Boost

GMAT Boost offers 250+ challenging GMAT Math practice questions, each with a thorough video explanation, and 100+ GMAT Math video tips, each 90 seconds or less.
It's a total of 20+ hours of expert instruction for an introductory price of just $10.
View sample questions and tips without signing up, or sign up now for full access.

Also, check out the most useful GMAT Math blog on the internet here.
Top
Newbie | Next Rank: 10 Posts
Posts: 9
Joined: Sat Aug 06, 2011 8:56 am

by waggrave » Mon Aug 15, 2011 1:30 pm
Thank you very much for your really clear answer. It's not in fact such a hard question, i feel stupid ! Thanks aniway :)
Top
Post new topic Post Reply
• Page 1 of 1