Find all School-related info fast with the new School-Specific MBA Forum

It is currently 21 Oct 2014, 10:40

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.

Events & Promotions

Events & Promotions in June
Open Detailed Calendar

If n is a multiple of 5, n=p^2q, where p and q are prime num

  Question banks Downloads My Bookmarks Reviews Important topics  
Author Message
TAGS:
Manager
Manager
User avatar
Joined: 12 Mar 2009
Posts: 192
Followers: 1

Kudos [?]: 94 [0], given: 60

If n is a multiple of 5, n=p^2q, where p and q are prime num [#permalink] New post 27 Sep 2009, 23:34
2
This post was
BOOKMARKED
00:00
A
B
C
D
E

Difficulty:

  35% (medium)

Question Stats:

63% (02:01) correct 37% (00:37) wrong based on 68 sessions
If n is a multiple of 5, n=p^2q, where p and q are prime numbers. Which of the following must be a multiple of 25?

A. p^2
B. q^2
C. pq
D. p^2q^2
E. p^3q

OPEN DISCUSSION OF THIS QUESTION IS HERE: if-is-n-is-multiple-of-5-and-n-p-2-q-where-p-and-q-are-prim-92383.html
[Reveal] Spoiler: OA

Attachments

PS02.jpg
PS02.jpg [ 47.81 KiB | Viewed 2525 times ]


Last edited by Bunuel on 25 Aug 2014, 03:33, edited 1 time in total.
Renamed the topic, edited the question and added the OA.
Kaplan Promo CodeKnewton GMAT Discount CodesManhattan GMAT Discount Codes
Manager
Manager
avatar
Joined: 11 Sep 2009
Posts: 129
Followers: 4

Kudos [?]: 179 [0], given: 6

Re: If n is a multiple of 5, n=p^2q, where p and q are prime num [#permalink] New post 27 Sep 2009, 23:50
The answer is D: p^2*q^2.

You are given that n = p^2 * q, which is a multiple of 5. Therefore p^2 * q is a multiple of 5. Since 5 is a prime number, p OR q must be a multiple of 5. Therefore, in order to be a multiple of 25, you must have a MINIMUM of p^2 * q^2 in the answer, since you don't know whether p or q is the multiple of 5. The only answer which satisfies this condition is D.
VP
VP
avatar
Status: There is always something new !!
Affiliations: PMI,QAI Global,eXampleCG
Joined: 08 May 2009
Posts: 1364
Followers: 12

Kudos [?]: 144 [0], given: 10

Re: If n is a multiple of 5, n=p^2q, where p and q are prime num [#permalink] New post 02 May 2011, 19:32
n = 5k = 20,45 etc.

20 = 2^2 * 5; 45 = 3^2 * 5

hence min solution possible is p^2 * q^2.
_________________

Visit -- http://www.sustainable-sphere.com/
Promote Green Business,Sustainable Living and Green Earth !!

Manager
Manager
avatar
Joined: 09 Aug 2010
Posts: 107
Followers: 1

Kudos [?]: 20 [0], given: 7

Re: If n is a multiple of 5, n=p^2q, where p and q are prime num [#permalink] New post 02 May 2011, 21:29
It is given that
n = p^2 (q)
n = 5(...)

We do not know whether p = 5 OR q = 5. There are 2 possibilities.

n = 5^2 (q)
OR
n = p^2 (5)

Since, we do not know whether p or q is 5 then. (A) and (B) could be eliminated.

(D) on the other hand raises both p and q to a power of 2. This guarantees 5 to be raised to 2 which is equivalent to 25.

Hence, D.
CEO
CEO
User avatar
Joined: 09 Sep 2013
Posts: 2804
Followers: 206

Kudos [?]: 42 [0], given: 0

Premium Member
Re: If n is a multiple of 5, n=p^2q, where p and q are prime num [#permalink] New post 24 Aug 2014, 15:54
Hello from the GMAT Club BumpBot!

Thanks to another GMAT Club member, I have just discovered this valuable topic, yet it had no discussion for over a year. I am now bumping it up - doing my job. I think you may find it valuable (esp those replies with Kudos).

Want to see all other topics I dig out? Follow me (click follow button on profile). You will receive a summary of all topics I bump in your profile area as well as via email.
_________________

GMAT Books | GMAT Club Tests | Best Prices on GMAT Courses | GMAT Mobile App | Math Resources | Verbal Resources

Expert Post
Math Expert
User avatar
Joined: 02 Sep 2009
Posts: 23355
Followers: 3604

Kudos [?]: 28717 [0], given: 2820

Re: If n is a multiple of 5, n=p^2q, where p and q are prime num [#permalink] New post 25 Aug 2014, 03:34
Expert's post
If n is multiple of 5, and n = p^2q where p and q are prime, which of the following must be a multiple of 25?

A p^2
B. q^2
C. pq
D. p^2q^2
E. p^3q

n=5k and n=p^2p, (p and q are primes).
Q: 25m=?

Well obviously either p or q is 5. As we are asked to determine which choice MUST be multiple of 25, right answer choice must have BOTH, p and q in power of 2 or higher to guarantee the divisibility by 25. Only D offers this.

Answer: D.

OPEN DISCUSSION OF THIS QUESTION IS HERE: if-is-n-is-multiple-of-5-and-n-p-2-q-where-p-and-q-are-prim-92383.html
_________________

NEW TO MATH FORUM? PLEASE READ THIS: ALL YOU NEED FOR QUANT!!!

PLEASE READ AND FOLLOW: 11 Rules for Posting!!!

RESOURCES: [GMAT MATH BOOK]; 1. Triangles; 2. Polygons; 3. Coordinate Geometry; 4. Factorials; 5. Circles; 6. Number Theory; 7. Remainders; 8. Overlapping Sets; 9. PDF of Math Book; 10. Remainders; 11. GMAT Prep Software Analysis NEW!!!; 12. SEVEN SAMURAI OF 2012 (BEST DISCUSSIONS) NEW!!!; 12. Tricky questions from previous years. NEW!!!;

COLLECTION OF QUESTIONS:
PS: 1. Tough and Tricky questions; 2. Hard questions; 3. Hard questions part 2; 4. Standard deviation; 5. Tough Problem Solving Questions With Solutions; 6. Probability and Combinations Questions With Solutions; 7 Tough and tricky exponents and roots questions; 8 12 Easy Pieces (or not?); 9 Bakers' Dozen; 10 Algebra set. ,11 Mixed Questions, 12 Fresh Meat

DS: 1. DS tough questions; 2. DS tough questions part 2; 3. DS tough questions part 3; 4. DS Standard deviation; 5. Inequalities; 6. 700+ GMAT Data Sufficiency Questions With Explanations; 7 Tough and tricky exponents and roots questions; 8 The Discreet Charm of the DS ; 9 Devil's Dozen!!!; 10 Number Properties set., 11 New DS set.


What are GMAT Club Tests?
25 extra-hard Quant Tests

Get the best GMAT Prep Resources with GMAT Club Premium Membership

Re: If n is a multiple of 5, n=p^2q, where p and q are prime num   [#permalink] 25 Aug 2014, 03:34
    Similar topics Author Replies Last post
Similar
Topics:
10 Experts publish their posts in the topic If n is a multiple of 5, n=p^2q, where p and q are prime num joyseychow 10 13 Aug 2009, 20:06
If n is a multiple of 5 and n=p^2 *q, where p and q are tarek99 2 07 Dec 2007, 05:15
If n is a multiple of 5 and n=p^2 . q where p and q are Finding Perdition 1 13 Aug 2007, 01:44
1 IF N IS A MULTIPLE OF 5 AND N=(P^2) *Q , WHERE P AND Q ARE buffett76 1 28 May 2007, 04:14
If n is a multiple of 5 and n=p^2q, where p and q are prime jodeci 2 07 Apr 2006, 19:20
Display posts from previous: Sort by

If n is a multiple of 5, n=p^2q, where p and q are prime num

  Question banks Downloads My Bookmarks Reviews Important topics  


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

Powered by phpBB © phpBB Group and phpBB SEO

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®.