|
|
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
Track
Your Progress
Practice
Pays
Not interested in getting valuable practice questions and articles delivered to your email? No problem, unsubscribe here.
Updated on: 23 Jul 2012, 01:40
Originally posted by pathakshashi on 22 Jul 2012, 18:17.
Last edited by Bunuel on 23 Jul 2012, 01:40, edited 2 times in total.
Last edited by Bunuel on 23 Jul 2012, 01:40, edited 2 times in total.
Edited the question.
Kudos
Bookmarks
C
Be sure to select an answer first to save it in the Error Log before revealing the correct answer (OA)!
Difficulty:
35%
(medium)
Question Stats:
66% (01:28) correct
34%
(01:13)
wrong
based on 192
sessions
History
Date
Time
Result
Not Attempted Yet
If c and d are positive, is d an integer ?
(1) c=d^3
(2) \(d=\sqrt{c}\)
(1) c=d^3
(2) \(d=\sqrt{c}\)
Pure algebraic questions like this one are no longer part of the GMAT Data Sufficiency syllabus.
For relevant Data Sufficiency questions, please check the Data Sufficiency forum:
Data Sufficiency Forum
Data Sufficiency Forum
22 Jul 2012, 20:26
Kudos
Bookmarks
pathakshashi
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!
23 Jul 2012, 01:50
Kudos
Bookmarks
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.
(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.
