Author 
Message 
TAGS:

Hide Tags

Current Student
Joined: 06 Oct 2009
Posts: 94
Location: Mexico
Concentration: Entrepreneurship, Finance
GPA: 3.85
WE: Sales (Commercial Banking)

If k is not equal to 0, 1, or 1 is 1/k > 0?
[#permalink]
Show Tags
10 Aug 2010, 12:05
Question Stats:
63% (00:48) correct 37% (01:09) wrong based on 346 sessions
HideShow timer Statistics
If k is not equal to 0, 1, or 1 is 1/k > 0? (1) 1/(k1) > 0 (2) 1/(k+1) > 0 My method for this sort of questions is way underdeveloped. I will appreciate any hints on how to tackle this sort of problems. Many thanks in advance.
Official Answer and Stats are available only to registered users. Register/ Login.




Math Expert
Joined: 02 Sep 2009
Posts: 48109

Re: If k does not equal 0, 1 or 1, is 1/k >0 (1) 1/(k1) > 0
[#permalink]
Show Tags
19 Feb 2012, 04:09




Math Expert
Joined: 02 Sep 2009
Posts: 48109

Re: Number Properties, Data sufficiency.
[#permalink]
Show Tags
10 Aug 2010, 12:25



Retired Moderator
Joined: 02 Sep 2010
Posts: 774
Location: London

Re: GMAT Prep: Inequalities
[#permalink]
Show Tags
05 Sep 2010, 02:46
IF (1) is true, it implies K>1, which implies 1/K > 0 If (2) is true, it implies K>1, which gives no information on the sign on 1/K So (1) alone without (2) is sufficient to answer the question
_________________
Math writeups 1) Algebra101 2) Sequences 3) Set combinatorics 4) 3D geometry
My GMAT story
GMAT Club Premium Membership  big benefits and savings



Math Expert
Joined: 02 Sep 2009
Posts: 48109

Re: GMAT Prep CAT Inequalities question
[#permalink]
Show Tags
21 Dec 2010, 01:20



Current Student
Joined: 21 Aug 2010
Posts: 194

If k does not equal 0, 1 or 1, is 1/k >0 (1) 1/(k1) > 0
[#permalink]
Show Tags
Updated on: 19 Feb 2012, 04:08
If k does not equal 0, 1 or 1, is 1/k >0
(1) 1/(k1) > 0 (2) 1/(k+1) > 0
Originally posted by samramandy on 24 Aug 2011, 11:24.
Last edited by Bunuel on 19 Feb 2012, 04:08, edited 1 time in total.
Edited the question and added the OA



Manager
Status: Persevering
Joined: 15 May 2013
Posts: 193
Location: India
Concentration: Technology, Leadership
GMAT Date: 08022013
GPA: 3.7
WE: Consulting (Consulting)

Re: If k <> 0, 1, or 1, is 1/k > 0 ?
[#permalink]
Show Tags
25 Aug 2013, 05:32
It must be A. Again it is not mentioned that k is an integer. 1) 1/k1>0 => k can be any value greater than 1 to satisfy this equation hence 1/k >0; sufficient. 2) 1/1+k>0 => if k=0.5 then 1/k >0 it holds true, but if k=0.5 this equation still holds whereas, 1/k<0; therefore not sufficient.  Ramandeep
_________________
It's one thing to get defeated, but another to accept it.



Manager
Joined: 13 Jun 2012
Posts: 180
Location: United States
WE: Supply Chain Management (Computer Hardware)

Re: If k does not equal 0, 1 or 1, is 1/k >0 (1) 1/(k1) > 0
[#permalink]
Show Tags
17 Aug 2015, 08:28
Bunuel wrote: Turkish wrote: Bunuel wrote: 1. If k#0, 1 or 1 is \(\frac{1}{k}> 0\)?
(1) \(\frac{1}{k1}> 0\) > \(k1>0\)> \(k>1\), hence \(\frac{1}{k}>0\). Sufficient.
(2) \(\frac{1}{k+1}> 0\)> \(k+1>0\) > \(k>1\), hence \(k\) can be negative as well as positive: \(\frac{1}{k}\) may or may not be \(>0\). Not sufficient.
Answer: A. Hello Bunuel, I am not getting this. why is is k>0? Thanks Turk Which statement are you referring to? In your explanation you said " Basically the question asks: is k>0? " I am not getting how the question is asking whether k>0?



Math Expert
Joined: 02 Sep 2009
Posts: 48109

Re: If k does not equal 0, 1 or 1, is 1/k >0 (1) 1/(k1) > 0
[#permalink]
Show Tags
17 Aug 2015, 08:32



Manager
Joined: 29 Dec 2014
Posts: 69

Re: If k does not equal 0, 1 or 1, is 1/k >0 (1) 1/(k1) > 0
[#permalink]
Show Tags
30 Jan 2016, 07:50
Bunuel wrote: If k#0, 1 or 1 is \(\frac{1}{k}> 0\)?
Basically the question asks: is \(k>0\)?
(1) \(\frac{1}{k1}> 0\) > denominator is positive: \(k1>0\)> \(k>1\), hence \(\frac{1}{k}>0\). Sufficient.
(2) \(\frac{1}{k+1}> 0\)> denominator is positive: \(k+1>0\) > \(k>1\), hence \(k\) can be negative as well as positive: \(\frac{1}{k}\) may or may not be \(>0\). Not sufficient.
Answer: A.
Hope it's clear. A very fundamental or maybe silly question regarding such questions: when we are deducing from (1/K)>0 > K>0.. how are we doing that, as assuming 0/0 on the RHS would be undefined. Thanks



Current Student
Joined: 20 Mar 2014
Posts: 2643
Concentration: Finance, Strategy
GPA: 3.7
WE: Engineering (Aerospace and Defense)

Re: If k does not equal 0, 1 or 1, is 1/k >0 (1) 1/(k1) > 0
[#permalink]
Show Tags
30 Jan 2016, 08:04
WilDThiNg wrote: Bunuel wrote: If k#0, 1 or 1 is \(\frac{1}{k}> 0\)?
Basically the question asks: is \(k>0\)?
(1) \(\frac{1}{k1}> 0\) > denominator is positive: \(k1>0\)> \(k>1\), hence \(\frac{1}{k}>0\). Sufficient.
(2) \(\frac{1}{k+1}> 0\)> denominator is positive: \(k+1>0\) > \(k>1\), hence \(k\) can be negative as well as positive: \(\frac{1}{k}\) may or may not be \(>0\). Not sufficient.
Answer: A.
Hope it's clear. A very fundamental or maybe silly question regarding such questions: when we are deducing from (1/K)>0 > K>0.. how are we doing that, as assuming 0/0 on the RHS would be undefined. Thanks No, we are not assuming 0/0. When you are given a/b > 0 this means that the fraction a/b > 0 > 2 cases possible, Case 1, either both a,b > 0 or Case 2, both a,b < 0. You can try the following examples to see the above 2 cases: Case 1: a=1, b = 2, a/b = 0.5 > 0 Case 2, a=1, b = 5 , a/b = 0.2 > 0 But if lets say you have a=1 and b = 2 or a=2 and b= 3 , a/b <0 and NOT >0. You can even remember this that in order for a fraction a/b to be >0 > both a,b MUST have the same signs. Either both of them are >0 or both of them are negative. Coming back to the question, When you are given 1/k > 0 > 1 is already >0 so based on the 'rule' above, k must also be positive in order for 1 and k to have the same 'sign'. Thus k>0. Similarly, if 1/(k1) > 0 > k1 > 0 > k >1 etc. Hope this helps.



Math Revolution GMAT Instructor
Joined: 16 Aug 2015
Posts: 6045
GPA: 3.82

Re: If k does not equal 0, 1 or 1, is 1/k >0 (1) 1/(k1) > 0
[#permalink]
Show Tags
01 Feb 2016, 05:34
Forget conventional ways of solving math questions. In DS, Variable approach is the easiest and quickest way to find the answer without actually solving the problem. Remember equal number of variables and independent equations ensures a solution. If k does not equal 0, 1 or 1, is 1/k >0 (1) 1/(k1) > 0 (2) 1/(k+1) > 0 When it comes to inequality DS questions, 2 things are important at all times. First is square. Secondly, when range of que includes range of con, the con is sufficient. Modify the original condition and the question. Multiply k^2 on the both equations and the sign of inequality doesn't change as k^2 is still a positive integer even when it's multiplied. There is 1 variable(k), which should match with the number of equations. So you need 1 equation, for 1) 1 equation, for 2) q equation, which is likely to make D the answer. For 1), multiply (k1)^2 on the both equations, they become k1>0, k>1. The range of que includes the range of con, which is sufficient. For 2), multiply (k1)^2 on the both equations, they become k1>0, k>1. The range of que doesn't include the range of con, which is not sufficient Therefore, the answer is A. > For cases where we need 1 more equation, such as original conditions with “1 variable”, or “2 variables and 1 equation”, or “3 variables and 2 equations”, we have 1 equation each in both 1) and 2). Therefore, there is 59 % chance that D is the answer, while A or B has 38% chance and C or E has 3% chance. Since D is most likely to be the answer using 1) and 2) separately according to DS definition. Obviously there may be cases where the answer is A, B, C or E.
_________________
MathRevolution: Finish GMAT Quant Section with 10 minutes to spare The oneandonly World’s First Variable Approach for DS and IVY Approach for PS with ease, speed and accuracy. "Only $99 for 3 month Online Course" "Free Resources30 day online access & Diagnostic Test" "Unlimited Access to over 120 free video lessons  try it yourself"



Current Student
Joined: 12 Aug 2015
Posts: 2650

Re: If k is not equal to 0, 1, or 1 is 1/k > 0?
[#permalink]
Show Tags
07 Mar 2016, 21:58
Bull78 wrote: If k is not equal to 0, 1, or 1 is 1/k > 0?
(1) 1/(k1) > 0 (2) 1/(k+1) > 0
My method for this sort of questions is way underdeveloped. I will appreciate any hints on how to tackle this sort of problems. Many thanks in advance. Fun Fact => if K was an integer than then D would be the choice.
_________________
MBA Financing: INDIAN PUBLIC BANKS vs PRODIGY FINANCE! Getting into HOLLYWOOD with an MBA! The MOST AFFORDABLE MBA programs!STONECOLD's BRUTAL Mock Tests for GMATQuant(700+)AVERAGE GRE Scores At The Top Business Schools!



Intern
Joined: 06 Jan 2016
Posts: 24
Location: Spain
Concentration: Operations, General Management

Re: If k does not equal 0, 1 or 1, is 1/k >0 (1) 1/(k1) > 0
[#permalink]
Show Tags
20 Dec 2017, 11:14
stonecold wrote: Bull78 wrote: If k is not equal to 0, 1, or 1 is 1/k > 0?
(1) 1/(k1) > 0 (2) 1/(k+1) > 0
My method for this sort of questions is way underdeveloped. I will appreciate any hints on how to tackle this sort of problems. Many thanks in advance. Fun Fact => if K was an integer than then D would be the choice. So fun, that I, in fact, committed that mistake xD




Re: If k does not equal 0, 1 or 1, is 1/k >0 (1) 1/(k1) > 0 &nbs
[#permalink]
20 Dec 2017, 11:14






