GMAT Question of the Day - Daily to your Mailbox; hard ones only

It is currently 17 Feb 2019, 07:57

Close

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
Your Progress

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

Not interested in getting valuable practice questions and articles delivered to your email? No problem, unsubscribe here.

Close

Request Expert Reply

Confirm Cancel
Events & Promotions in February
PrevNext
SuMoTuWeThFrSa
272829303112
3456789
10111213141516
17181920212223
242526272812
Open Detailed Calendar
  • Free GMAT Algebra Webinar

     February 17, 2019

     February 17, 2019

     07:00 AM PST

     09:00 AM PST

    Attend this Free Algebra Webinar and learn how to master Inequalities and Absolute Value problems on GMAT.
  • Valentine's day SALE is on! 25% off.

     February 18, 2019

     February 18, 2019

     10:00 PM PST

     11:00 PM PST

    We don’t care what your relationship status this year - we love you just the way you are. AND we want you to crush the GMAT!

If two integers p and q are in the ratio 4: 5 and their least common m

  new topic post reply Question banks Downloads My Bookmarks Reviews Important topics  
Author Message
Manager
Manager
User avatar
G
Joined: 13 May 2017
Posts: 103
Location: Finland
Concentration: Accounting, Entrepreneurship
GMAT 1: 530 Q42 V22
GPA: 3.14
WE: Account Management (Entertainment and Sports)
CAT Tests
If two integers p and q are in the ratio 4: 5 and their least common m  [#permalink]

Show Tags

New post 09 Oct 2018, 05:01
1
00:00
A
B
C
D
E

Difficulty:

  65% (hard)

Question Stats:

53% (01:24) correct 47% (02:14) wrong based on 30 sessions

HideShow timer Statistics

If two integers p and q are in the ratio 4: 5 and their least common multiple is 800, what is their greatest common divisor?

A. 20
B. 40
C. 80
D. 100
E. 160
Math Expert
User avatar
V
Joined: 02 Aug 2009
Posts: 7334
Premium Member Reviews Badge
Re: If two integers p and q are in the ratio 4: 5 and their least common m  [#permalink]

Show Tags

New post 09 Oct 2018, 05:28
1
1
rencsee wrote:
If two integers p and q are in the ratio 4: 5 and their least common multiple is 800, what is their greatest common divisor?

A. 20
B. 40
C. 80
D. 100
E. 160


The product of two integers= GCD*LCM
So \(4x*5x=800*G......20x^2=800G.....x^2=40G\)
Now X as common ratio means G is x
So x^2=40x or X=40
_________________

1) Absolute modulus : http://gmatclub.com/forum/absolute-modulus-a-better-understanding-210849.html#p1622372
2)Combination of similar and dissimilar things : http://gmatclub.com/forum/topic215915.html
3) effects of arithmetic operations : https://gmatclub.com/forum/effects-of-arithmetic-operations-on-fractions-269413.html
4) Base while finding % increase and % decrease : https://gmatclub.com/forum/percentage-increase-decrease-what-should-be-the-denominator-287528.html


GMAT Expert

Manager
Manager
User avatar
S
Joined: 01 Nov 2017
Posts: 94
GMAT 1: 700 Q50 V35
GMAT 2: 640 Q49 V28
GMAT 3: 680 Q47 V36
GMAT 4: 700 Q50 V35
Re: If two integers p and q are in the ratio 4: 5 and their least common m  [#permalink]

Show Tags

New post 09 Oct 2018, 06:06
We have:
P = 4 * x
Q = 5 * x
LCM = 800 = 2^5 * 5^2
=> 4 * 5 * x = 2^2 * 5 * 2^3 * 5
=> x = 2^3 * 5 = 8 * 5 = 40
Because 4 and 5 have no common multiple -> x is the GCD = 40
Intern
Intern
avatar
B
Joined: 13 Jan 2016
Posts: 9
Re: If two integers p and q are in the ratio 4: 5 and their least common m  [#permalink]

Show Tags

New post 09 Oct 2018, 21:09
VodkaHelps wrote:
We have:
P = 4 * x
Q = 5 * x
LCM = 800 = 2^5 * 5^2
=> 4 * 5 * x = 2^2 * 5 * 2^3 * 5
=> x = 2^3 * 5 = 8 * 5 = 40
Because 4 and 5 have no common multiple -> x is the GCD = 40


if they have no common multiple then shouldn't GCF be 1 ?
GMAT Club Bot
Re: If two integers p and q are in the ratio 4: 5 and their least common m   [#permalink] 09 Oct 2018, 21:09
Display posts from previous: Sort by

If two integers p and q are in the ratio 4: 5 and their least common m

  new topic post reply Question banks Downloads My Bookmarks Reviews Important topics  


Copyright

GMAT Club MBA Forum Home| About| Terms and Conditions and Privacy Policy| GMAT Club Rules| Contact| Sitemap

Powered by phpBB © phpBB Group | Emoji artwork provided by EmojiOne

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®.