Author 
Message 
TAGS:

Hide Tags

Manager
Joined: 24 Aug 2010
Posts: 169
Location: Finland
Schools: Admitted: IESE($$),HEC, RSM,Esade
WE 1: 3.5 years international

If n is an integer and n^3 is between 1 and 100, inclusive, what is [#permalink]
Show Tags
19 Oct 2010, 11:25
2
This post received KUDOS
1
This post was BOOKMARKED
Question Stats:
62% (01:05) correct 38% (00:59) wrong based on 119 sessions
HideShow timer Statistics
If n is an integer and n^3 is between 1 and 100, inclusive, what is the value of n? (1) n = 2k+1, where k is an integer. (2) n is a prime number. Need help on this question which is explained in the Number Properties book by Manhattan. According to Manhattan, the OA is C, but to me, the OA should be A. We know that n>0 because n^3 is between 1 and 100, so n is a positive integer. The value of n could be 1, 2, 3, and 4. Statement 1: n = 2k+1. So n is an odd number. So n is either 1 or 3. According to MGMAT, statement 1 is not sufficient to answer the question because n could be either 1 or 3 and so there is not a unique value of n as it yields two possible values. But this is where I beg to differ. According to me, the value of n could be only 3 (n = 2*1+1). Tell me where I am wrong.
Official Answer and Stats are available only to registered users. Register/ Login.



Math Expert
Joined: 02 Sep 2009
Posts: 44599

If n is an integer and n^3 is between 1 and 100, inclusive, what is [#permalink]
Show Tags
19 Oct 2010, 12:00
shekharvineet wrote: Need help on this question which is explained in the Number Properties book by Manhattan. According to Manhattan, the OA is C, but to me, the OA should be A. If n is an integer and n^3 is between 1 and 100, inclusive, what is the value of n? (1). n = 2k+1, where k is an integer. (2). n is a prime number. We know that n>0 because n^3 is between 1 and 100, so n is a positive integer. The value of n could be 1, 2, 3, and 4. Statement 1: n = 2k+1. So n is an odd number. So n is either 1 or 3. According to MGMAT, statement 1 is not sufficient to answer the question because n could be either 1 or 3 and so there is not a unique value of n as it yields two possible values. But this is where I beg to differ. According to me, the value of n could be only 3 (n = 2*1+1). Tell me where I am wrong. If n is an integer and n^3 is between 1 and 100, inclusive, what is the value of n?n is an integer and \(n^3\) is between 1 and 100, inclusive, means that n could be 1, 2, 3 or 4 (but not 5 or more since 5^3 = 125 > 100). (1) n = 2k+1, where k is an integer > n is an odd number > n could be 1 or 3. Not sufficient. (2) n is a prime number > n could be 2 or 3. Not sufficient. (1)+(2) n could be only 3. Sufficient. Answer: C. shekharvineet wrote: Need help on this question which is explained in the Number Properties book by Manhattan. According to Manhattan, the OA is C, but to me, the OA should be A. If n is an integer and n^3 is between 1 and 100, inclusive, what is the value of n? (1). n = 2k+1, where k is an integer. (2). n is a prime number. We know that n>0 because n^3 is between 1 and 100, so n is a positive integer. The value of n could be 1, 2, 3, and 4. Statement 1: n = 2k+1. So n is an odd number. So n is either 1 or 3. According to MGMAT, statement 1 is not sufficient to answer the question because n could be either 1 or 3 and so there is not a unique value of n as it yields two possible values. But this is where I beg to differ. According to me, the value of n could be only 3 (n = 2*1+1). Tell me where I am wrong. As for your doubt: \(n=2k+1\), where k is an integer is a formula of an odd number so you can get ANY odd number with it, including 1: if k = 0 then \(n=2k+1=1\). Hope it helps.
_________________
New to the Math Forum? Please read this: Ultimate GMAT Quantitative Megathread  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? Extrahard Quant Tests with Brilliant Analytics



Manager
Joined: 24 Aug 2010
Posts: 169
Location: Finland
Schools: Admitted: IESE($$),HEC, RSM,Esade
WE 1: 3.5 years international

Re: If n is an integer and n^3 is between 1 and 100, inclusive, what is [#permalink]
Show Tags
19 Oct 2010, 12:21
Thanks. It cleared my doubt, especially the last part in your solution where you talk about the value of the integer k. I simply forgot the fact that 0 is and integer and so n could be 1 or 3. thats the reason why I was getting 3 as the only value of n from the 1st statement. +1 to you.



Manager
Joined: 25 Aug 2010
Posts: 69

Re: If n is an integer and n^3 is between 1 and 100, inclusive, what is [#permalink]
Show Tags
20 Oct 2010, 06:11
(1) n = 2k+1, where k is an integer >
so K can take  4 3 2 1 0 1 2 3 4  but if i take any negative it wont be between 1 and 100 as a power cube.. so negative numbers out. from n = 2K + 1 ===> k should be either 0 or 2 if it is 3 then n = so i should consider only 0,1,2,3,.....
but n = 2k + 1 and n^3 is between 1 and 100 inclusive... there could be a chance of 2 values for n
if k = 0, then n = 1 ===> n^3 =1 <= 100 K = 1, then n= 3 ===> n^3 = 27 <= 100 k = 2 then n = 5 ====> n^3 = 5^3 = 125 > 100
So from 1 only 2 possible values 1 and 3 for the N (2) n is a prime number > could be 2 or 3 >
So the n value from the both (1) and (2) is 3



Manager
Joined: 02 Jun 2011
Posts: 136

Re: If n is an integer and n^3 is between 1 and 100, inclusive, what is [#permalink]
Show Tags
05 Jun 2012, 12:34
1
This post received KUDOS
given n*n*n = inclusive 1  100 St.1 ) n = 2k+1 implies n is odd and n*n*n = 1  100, n= 1, 3  NOT sufficient
St.2) n=prime no. implies n= 2,3 (as again n*n*n = 1 100) NOT sufficient
St.1) and St. 2) = 3, sufficient.
Answer  C



Intern
Joined: 30 Apr 2012
Posts: 47
Location: India
Concentration: Finance, Human Resources
GPA: 3.31
WE: Information Technology (Computer Software)

Re: If n is an integer and n^3 is between 1 and 100, inclusive, what is [#permalink]
Show Tags
05 Jun 2012, 14:40
kashishh wrote: given n*n*n = inclusive 1  100 St.1 ) n = 2k+1 implies n is odd and n*n*n = 1  100, n= 1, 3  NOT sufficient
St.2) n=prime no. implies n= 2,3 (as again n*n*n = 1 100) NOT sufficient
St.1) and St. 2) = 3, sufficient.
Answer  C thanks a lot......i need 1 more help....while solving quant section,most of my questions on inequalities,probablity,standard deviation etc are always gettin wrong....ny idea from where should i study these...... regards, mudit
_________________
Your KUDOS will keep me inspired in contributing more to this community......



NonHuman User
Joined: 09 Sep 2013
Posts: 6649

Re: If n is an integer and n^3 is between 1 and 100, inclusive, what is [#permalink]
Show Tags
13 Dec 2017, 23:38
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 n is an integer and n^3 is between 1 and 100, inclusive, what is
[#permalink]
13 Dec 2017, 23:38






