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

Redeem

Target Test Prep · GMAT

Choose how you want to prepare

Learn live with an expert or move at your own pace. Every option includes the complete TTP study system.

★★★★★5.0559 reviews
Vote for Target Test Prep, Newsweek Readers’ Choice Awards 2026
NEWSWEEK READERS’ CHOICE 2026

BIG NEWS! Target Test Prep has been nominated, and they’d love your vote!

TTP has worked incredibly hard to build the best test prep experience possible, and winning Newsweek’s 2026 Readers’ Choice Award for Best Test Prep would mean a lot to them. If TTP has helped you, they’d be incredibly grateful for your vote. You can vote once each day through September 9.

Vote for TTP
GMATLiveTeach 7 seats left
Chris Peckover
NEXT LIVE COHORT

Oct 13 to Jan 7, 2027

with Chris Peckover

Schedule
Tue, Thu · 8:00 to 10:00 PM ET
Included
40 live hours + 6 months of GMAT OnDemand
  • Live instruction and real-time questions
  • Class recordings and assigned practice
View class & enroll
Limited cohort · enrollment openTarget Test Prep
EALiveTeach 5 seats left
Logan Thompson
EXECUTIVE ASSESSMENT

Sep 6 to Dec 6, 2026

with Logan Thompson

Schedule
Sun · 9:30 AM to 12:30 PM ET
Included
40 hours of live online classes plus six months of access to the complete TTP EA OnDemand course.
  • 165+ EA Score Guarantee
  • 4,100+ Quant, Verbal, and Integrated Reasoning practice questions
  • 400+ hours of in-depth video lessons
  • 3,000+ step-by-step video solutions
View EA class & enroll
Limited cohort · enrollment openTarget Test Prep
GMATOnDemand Start anytime
SELF-PACED MASTERCLASS

Target Test Prep GMAT OnDemand

Complete access from day one. Study on your schedule.

715+ score guarantee
$0to start then $127/mo
  • Personalized study plan and analytics
  • Thousands of lessons and practice questions
Start free 5-day trial
Read 559 reviewsTarget Test Prep

Compare the format, schedule, and included access before enrolling. Prices and seat counts shown reflect the supplied offer details.

GMAT Prep question - really tough one - LCM, GCF factor etc.

Expert replies
Post new topic Post Reply
Previous Topic Next Topic

GMAT/MBA Expert

User avatar
GMAT Instructor
Posts: 3380
Joined: Mon Mar 03, 2008 1:20 amFollowed by: 1535 members
Thanked: 2256 times
GMAT Score:800

by lunarpower » Sun Jul 05, 2009 3:58 am
@ navalpike
navalpike wrote:P=m+r
2s=2k+r
2s-2k=r
2(s-k)=r
your heart's in the right place, but this needs a little overhaul.

specifically:
"p = m + r" is wrong, unless 'm' goes into 'p' EXACTLY ONCE and then leaves a remainder. (for instance, if i want the remainder when i divide 200 by 6, i clearly can't write 200 = 6 + r; that will give an absolutely absurd remainder.)

still, you can use this method. here's the refinement:
in general, 'm' will divide into 'p' some integer number of times, say 'j', and leave a remainder.
therefore,
p = jm + r
2s = 2jk + r
2s - 2jk = r
then factor out the '2' and proceed as before.
Ron has been teaching various standardized tests for 20 years.

--

Pueden hacerle preguntas a Ron en castellano
Potete chiedere domande a Ron in italiano
On peut poser des questions à Ron en français
Voit esittää kysymyksiä Ron:lle myös suomeksi

--

Quand on se sent bien dans un vêtement, tout peut arriver. Un bon vêtement, c'est un passeport pour le bonheur.

Yves Saint-Laurent

--

Learn more about ron
Top
Join the discussion
Log in to postLogin with Googleuse password
QUOTE IN REPLY
Master | Next Rank: 500 Posts
Posts: 103
Joined: Mon May 04, 2009 11:53 am
Thanked: 6 times

by navalpike » Sun Jul 05, 2009 9:40 am
Ahhh, I can't believe I did that. Thanks for correcting me.

Ron, as my post stated above, do you know of a similar algebraic approach that we can apply to S2. As I mentioned, the first time around I got the question wrong and chose D because I failed to consider the right numbers for LCM 30.

Thanks,
Top
Join the discussion
Log in to postLogin with Googleuse password
QUOTE IN REPLY

GMAT/MBA Expert

User avatar
GMAT Instructor
Posts: 3380
Joined: Mon Mar 03, 2008 1:20 amFollowed by: 1535 members
Thanked: 2256 times
GMAT Score:800

by lunarpower » Sun Jul 05, 2009 10:59 pm
navalpike wrote:Ahhh, I can't believe I did that. Thanks for correcting me.

Ron, as my post stated above, do you know of a similar algebraic approach that we can apply to S2. As I mentioned, the first time around I got the question wrong and chose D because I failed to consider the right numbers for LCM 30.

Thanks,
unfortunately, no, i can't think of a simple algebraic approach for numbers with a given LCM.
(you could try to write the numbers as something like 30/m and 30/n, but whatever you do with those numbers is going to be obnoxiously difficult. worse yet, the 'm' and 'n' in these expressions are the EXACT SAME numbers that you'll get if you just let 'm' and 'n' represent the factors themselves.)

this is how a LOT of gmat divisibility problems work, by the way. in fact, i'd say that, among divisibility problems, there are probably more problems that DON'T have simple all-algebraic solutions than problems that do have such solutions.
Ron has been teaching various standardized tests for 20 years.

--

Pueden hacerle preguntas a Ron en castellano
Potete chiedere domande a Ron in italiano
On peut poser des questions à Ron en français
Voit esittää kysymyksiä Ron:lle myös suomeksi

--

Quand on se sent bien dans un vêtement, tout peut arriver. Un bon vêtement, c'est un passeport pour le bonheur.

Yves Saint-Laurent

--

Learn more about ron
Top
Join the discussion
Log in to postLogin with Googleuse password
QUOTE IN REPLY
User avatar
Senior | Next Rank: 100 Posts
Posts: 75
Joined: Fri Jun 26, 2015 7:43 am

by gmat_for_life » Mon Apr 25, 2016 7:17 pm
Hello experts,

I was going through Ron's solution to this question. I realized that we have to pick numbers whose LCM is 30. Could you please let me know how to pick such numbers? Its easy to find the LCM when the numbers are given but to find those 2 numbers when the LCM is given is a bit confusing.

Regards,
Amit
Top
Join the discussion
Log in to postLogin with Googleuse password
QUOTE IN REPLY
Newbie | Next Rank: 10 Posts
Posts: 1
Joined: Mon Feb 12, 2018 2:02 am

TTT

by moonavav » Mon Feb 12, 2018 2:28 am
It is quite simple.

The question asks us if the remainder is greater than one or not?

lets assume the remainder is 0 or 1.

Scenario 1 (remainder is zero):
This is not possible due to the fact that p is not divisible by m.

Scenario 2 (remainder is one):
This is not also possible because consecutive numbers can have a remainder of one. and since both numbers are even (GCF is 2), the remainder is greater than one.

As a result, Statement 1 is sufficient for answering the question.

Lets take Statement 2:
LCM is 30. Lets state all of possible numbers that m and p can have:
1 2 3 5 6 10 15 30

Well, 1 and 2 will be omitted (the question tells us m and p are greater than 2) and the others will remain:

if p=10 and m=6, the remainder will be greater than 1
and
if p=6 and m=5, the remainder will be one.

So statement 2 is insufficient for answering the problem and the answer will be A.

<i class="em em-heart_eyes"></i><i class="em em-heart_eyes"></i>
Top
Join the discussion
Log in to postLogin with Googleuse password
QUOTE IN REPLY
Post new topic Post Reply