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

It is currently 26 Sep 2016, 19:03
GMAT Club Tests

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 c and d are positive, is d an integer ?

  new topic post reply Question banks Downloads My Bookmarks Reviews Important topics  
Author Message
TAGS:

Hide Tags

1 KUDOS received
Intern
Intern
avatar
Joined: 12 Jun 2011
Posts: 2
Followers: 0

Kudos [?]: 2 [1] , given: 0

If c and d are positive, is d an integer ? [#permalink]

Show Tags

New post 22 Jul 2012, 18:17
1
This post received
KUDOS
1
This post was
BOOKMARKED
00:00
A
B
C
D
E

Difficulty:

  35% (medium)

Question Stats:

67% (01:00) correct 33% (00:38) wrong based on 58 sessions

HideShow timer Statistics

If c and d are positive, is d an integer ?

(1) c=d^3
(2) \(d=\sqrt{c}\)
[Reveal] Spoiler: OA

Last edited by Bunuel on 23 Jul 2012, 01:40, edited 2 times in total.
Edited the question.
Senior Manager
Senior Manager
User avatar
Joined: 11 May 2011
Posts: 373
Location: US
Followers: 3

Kudos [?]: 91 [0], given: 46

Re: If c & d are positive, is d an integer? [#permalink]

Show Tags

New post 22 Jul 2012, 20:26
pathakshashi wrote:
If c & d are positive, is d an integer ?
i) c=d^3
ii) d=\sqrt{c}


My answer is C and below is the explanation.
i) c=d^3 -> c & d can have multiple fraction values to satisfy this equation. Hence Insuff.
ii) d=\sqrt{c} -> Here as well, c & d can have multiple fraction values to satisfy this equation. Hence Insuff.

Putting together -> d = square_root (d^3) and this equation can have only one value, which is d =1. Hence C is the answer.

Cheers!
_________________

-----------------------------------------------------------------------------------------
What you do TODAY is important because you're exchanging a day of your life for it!
-----------------------------------------------------------------------------------------

Expert Post
Math Expert
User avatar
Joined: 02 Sep 2009
Posts: 34862
Followers: 6485

Kudos [?]: 82733 [0], given: 10116

Re: If c and d are positive, is d an integer ? [#permalink]

Show Tags

New post 23 Jul 2012, 01:50
Expert's post
1
This post was
BOOKMARKED
If c and d are positive, is d an integer ?

(1) c=d^3. If \(c\) is a perfect cube (for example 1^3=1, 2^3=8, 3^3=27, ...), then the answer is YES but if \(c\) is NOT a perfect cube (for xample if \(c=2\)), then the answer is NO. Not sufficient.

(2) \(d=\sqrt{c}\) --> \(c=d^2\). The same here: if \(c\) is a perfect square (for example 1^2=1, 2^3=4, 3^2=9, ...), then the answer is YES but if \(c\) is NOT a perfect square (for xample if \(c=2\)), then the answer is NO. Not sufficient.

(1)+(2) From above we have that \(d^3=d^2\) --> \(d^3-d^2=0\) --> \(d^2(d-1)=0\) --> \(d=0\) (not a valid solution since we are told that \(d\) must be positive) or \(d=1=integer\). Sufficient.

Answer: C.

Hope it's clear.
_________________

New to the Math Forum?
Please read this: All You Need for Quant | PLEASE READ AND FOLLOW: 12 Rules for Posting!!!

Resources:
GMAT Math Book | Triangles | Polygons | Coordinate Geometry | Factorials | Circles | Number Theory | Remainders; 8. Overlapping Sets | PDF of Math Book; 10. Remainders | GMAT Prep Software Analysis | SEVEN SAMURAI OF 2012 (BEST DISCUSSIONS) | Tricky questions from previous years.

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?
Extra-hard Quant Tests with Brilliant Analytics

GMAT Club Legend
GMAT Club Legend
User avatar
Joined: 09 Sep 2013
Posts: 11689
Followers: 527

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

Premium Member
Re: If c and d are positive, is d an integer ? [#permalink]

Show Tags

New post 09 Nov 2015, 23:06
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

Re: If c and d are positive, is d an integer ?   [#permalink] 09 Nov 2015, 23:06
    Similar topics Author Replies Last post
Similar
Topics:
Experts publish their posts in the topic if c and d are positives integers, d>=2 and cd is the square nanocgo 3 27 Feb 2016, 08:49
9 Experts publish their posts in the topic If a, b, c, d, and e are positive integers such that Bunuel 6 19 Jun 2015, 02:07
13 Experts publish their posts in the topic A, B, C and D are positive integers such that A/B = C/D. Is C divisibl Bunuel 7 16 Apr 2015, 04:46
16 Experts publish their posts in the topic If N, C, and D are positive integers, what is the remainder kingb 14 06 Nov 2012, 18:35
16 Experts publish their posts in the topic If c and d are integers, is c even? tarek99 9 25 Jul 2008, 02:50
Display posts from previous: Sort by

If c and d are positive, is d an integer ?

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


GMAT Club MBA Forum Home| About| 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®.