Oct 16 08:00 PM PDT  09:00 PM PDT EMPOWERgmat is giving away the complete Official GMAT Exam Pack collection worth $100 with the 3 Month Pack ($299) Oct 18 08:00 AM PDT  09:00 AM PDT Learn an intuitive, systematic approach that will maximize your success on Fillintheblank GMAT CR Questions. Oct 19 07:00 AM PDT  09:00 AM PDT Does GMAT RC seem like an uphill battle? eGMAT is conducting a free webinar to help you learn reading strategies that can enable you to solve 700+ level RC questions with at least 90% accuracy in less than 10 days. Sat., Oct 19th at 7 am PDT Oct 20 07:00 AM PDT  09:00 AM PDT Get personalized insights on how to achieve your Target Quant Score. Oct 22 08:00 PM PDT  09:00 PM PDT On Demand for $79. For a score of 4951 (from current actual score of 40+) AllInOne Standard & 700+ Level Questions (150 questions)
Author 
Message 
TAGS:

Hide Tags

VP
Joined: 30 Sep 2004
Posts: 1229
Location: Germany

x/x<x. which of the following must be true about x ?
[#permalink]
Show Tags
Updated on: 17 May 2017, 04:35
Question Stats:
34% (01:38) correct 66% (01:52) wrong based on 1567 sessions
HideShow timer Statistics
x/x<x. Which of the following must be true about x ? A. x > 1 B. x > 1 C. x < 1 D. x = 1 E. x^2 > 1 THE CORRECT ANSWER IS THERE IS NO DEBATE WHATSOEVER. PLEASE READ THE WHOLE DISCUSSION TO UNDERSTAND THE QUESTION BETTER.
Official Answer and Stats are available only to registered users. Register/ Login.
Originally posted by christoph on 06 Feb 2005, 09:16.
Last edited by Bunuel on 17 May 2017, 04:35, edited 5 times in total.
OA added.




Math Expert
Joined: 02 Sep 2009
Posts: 58380

Re: x/x<x. which of the following must be true about x ?
[#permalink]
Show Tags
01 Sep 2010, 07:32
x/x<x, which of the following must be true about x ? A. x>1 B. x>1 C. x<1 D. x=1 E. x^2>1 We are given that \(\frac{x}{x}<x\) (this is a true inequality), so first of all we should find the ranges of \(x\) for which this inequality holds true. \(\frac{x}{x}< x\) multiply both sides of inequality by \(x\) (side note: we can safely do this as absolute value is nonnegative and in this case we know it's not zero too) > \(x<xx\) > \(x(x1)>0\): Either \(x>0\) and \(x1>0\), so \(x>1\) or \(x<1\) > \(x>1\); Or \(x<0\) and \(x1<0\), so \(1<x<1\) > \(1<x<0\). So we have that: \(1<x<0\) or \(x>1\). Note \(x\) is ONLY from these ranges. Option B says: \(x>1\) > ANY \(x\) from above two ranges would be more than 1, so B is always true. Answer: B. nonameee wrote: Quote: x/x<x. which of the following must be true about x ?
a) x>1 b) x>1 c) x<1 d) x=1 e) x^2>1 Bunuel, I think there's a mistake in the question or in the answer choices: Here's my solution: 1) x<0: x/x < x 1<x<0 2) x>=0 x/x<x x>1 The solution of the inequality is then: 1<x<0 union x>1 The answer can't be B, since let x=1/2. We get: (1/2)/(1/2) < (1/2) 1< 1/2 Contradiction. I think the answer should be A since it satisfies all the scenarios. Can you please clarify? The options are not supposed to be the solutions of inequality \(\frac{x}{x}<x\). Hope it's clear.
_________________




SVP
Joined: 03 Jan 2005
Posts: 1705

Re: x/x<x. which of the following must be true about x ?
[#permalink]
Show Tags
06 Feb 2005, 22:32
x/x<x
if x>0, then 1/x<1 ie, x>1
if x<0, then 1/(x)>1, ie, x>1
So combine these two, we know that x must be greater than 1.
baner is right, (B).




SVP
Joined: 03 Jan 2005
Posts: 1705

Re: x/x<x. which of the following must be true about x ?
[#permalink]
Show Tags
06 Feb 2005, 22:50
It doesn't say that all x greater than 1 would satisfy the equation. We get two range of x that satisfies the equation (1,0) and (1,infinite). All that the answer says is that every x in our solution ranges are greater than 1, which is true.



Director
Joined: 23 Apr 2010
Posts: 507

Re: x/x<x. which of the following must be true about x ?
[#permalink]
Show Tags
02 Sep 2010, 00:20
Bunuel, thanks for your reply. But I have to disagree with you because:
The answer can't be B, since let x=1/2. We get: (1/2)/(1/2) < (1/2) 1< 1/2 Contradiction.
What do you think about that?



Math Expert
Joined: 02 Sep 2009
Posts: 58380

x/x<x. which of the following must be true about x ?
[#permalink]
Show Tags
02 Sep 2010, 03:30
nonameee wrote: Bunuel, thanks for your reply. But I have to disagree with you because:
The answer can't be B, since let x=1/2. We get: (1/2)/(1/2) < (1/2) 1< 1/2 Contradiction.
What do you think about that? OA for this question is B and it's not wrong.Consider following: If \(x=5\), then which of the following must be true about \(x\):A. x=3 B. x^2=10 C. x<4 D. x=1 E. x>10 Answer is E (x>10), because as x=5 then it's more than 10. Or: If \(1<x<10\), then which of the following must be true about \(x\):A. x=3 B. x^2=10 C. x<4 D. x=1 E. x<120 Again answer is E, because ANY \(x\) from \(1<x<10\) will be less than 120 so it's always true about the number from this range to say that it's less than 120. The same with original question: If \(1<x<0\) or \(x>1\), then which of the following must be true about \(x\):A. x>1 B. x>1 C. x<1 D. x=1 E. x^2>1 As \(1<x<0\) or \(x>1\) then ANY \(x\) from these ranges would satisfy \(x>1\). So B is always true. \(x\) could be for example 1/2, 3/4, or 10 but no matter what \(x\) actually is it's IN ANY CASE more than 1. So we can say about \(x\) that it's more than 1. On the other hand A says that \(x>1\), which is not always true as \(x\) could be 1/2 and 1/2 is not more than 1. Hope it's clear.
_________________



Intern
Joined: 18 Feb 2010
Posts: 22

Re: x/x<x. which of the following must be true about x ?
[#permalink]
Show Tags
26 Oct 2010, 03:12
Hi Bunnuel, Can it be solved as
x/x<x
Hence 1/x<1
1/x<1 OR 1/x<1 when 1/x<1 then 1<x = x>1
when 1/x<1 then 1<x = x>1
The two possible outcomes are x>1 or x>1 The more restrictive is x>1 Hence B
Thanks Neelam



Math Expert
Joined: 02 Sep 2009
Posts: 58380

Re: x/x<x. which of the following must be true about x ?
[#permalink]
Show Tags
26 Oct 2010, 09:44
nades09 wrote: Hi Bunnuel, Can it be solved as
x/x<x
Hence 1/x<1
1/x<1 OR 1/x<1 when 1/x<1 then 1<x = x>1
when 1/x<1 then 1<x = x>1
The two possible outcomes are x>1 or x>1 The more restrictive is x>1 Hence B
Thanks Neelam No, that't not correct. First of all, when you are writing 1/x<1 from x/x<x you are reducing (dividing) inequality by x: Never multiply or reduce inequality by an unknown (a variable) unless you are sure of its sign since you do not know whether you must flip the sign of the inequality.Consider a simple inequality \(4>3\) and some variable \(x\). Now, you can't multiply (or divide) both parts of this inequality by \(x\) and write: \(4x>3x\), because if \(x=1>0\) then yes \(4*1>3*1\) but if \(x=1\) then \(4*(1)=4<3*(1)=3\). Similarly, you can not divide an inequality by \(x\) not knowing its sign. Next, inequality \(\frac{1}{x}<1\) holds true in the following ranges: \(x<1\) and \(x>1\) (and not: x>1 or x>1, which by the way simply means x>1). Hope it's clear.
_________________



Intern
Joined: 17 May 2009
Posts: 27
Location: United States
GPA: 3.62
WE: Corporate Finance (Manufacturing)

Re: x/x<x. which of the following must be true about x ?
[#permalink]
Show Tags
24 Jul 2011, 19:12
A graph helps me visualize these types of problems. If you graph \(\frac{x}{x}\) (red line) and \(x\) (blue line), the green areas represent the region in which the inequality \(\frac{x}{x}<x\) is satisfied. The question asks what MUST BE TRUE if the inequality holds. In other words, IF \(\frac{x}{x}<x\) IS SATISFIED, then what must be true of \(x\)? The green areas represent the regions where this inequality holds. What must be true of both green areas? The \(x\) values in both regions must be greater than \(1\). B is the correct answer.
Attachments
7242011 80316 PM.jpg [ 71.12 KiB  Viewed 3363 times ]



Retired Moderator
Joined: 27 Aug 2012
Posts: 1050

Re: x/x<x. which of the following must be true about x ?
[#permalink]
Show Tags
28 Dec 2012, 00:55
Bunuel wrote: OA for this question is B and it's not wrong.
Consider following: If \(x=5\), then which of the following must be true about \(x\): A. x=3 B. x^2=10 C. x<4 D. x=1 E. x>10
Answer is E (x>10), because as x=5 then it's more than 10.
Or: If \(1<x<10\), then which of the following must be true about \(x\): A. x=3 B. x^2=10 C. x<4 D. x=1 E. x<120
Again answer is E, because ANY \(x\) from \(1<x<10\) will be less than 120 so it's always true about the number from this range to say that it's less than 120.
The same with original question:
If \(1<x<0\) or \(x>1\), then which of the following must be true about \(x\): A. x>1 B. x>1 C. x<1 D. x=1 E. x^2>1
As \(1<x<0\) or \(x>1\) then ANY \(x\) from these ranges would satisfy \(x>1\). So B is always true.
\(x\) could be for example 1/2, 3/4, or 10 but no matter what \(x\) actually is it's IN ANY CASE more than 1. So we can say about \(x\) that it's more than 1.
On the other hand A says that \(x>1\), which is not always true as \(x\) could be 1/2 and 1/2 is not more than 1.
Hope it's clear.
Bunuel, As you've mentioned that we're to verify the range of x for which the given inequality holds good. So for x>1, x can have the value like 1/2. So in that case the inequality doesn't hold good for sure. Aren't we validating the inequality to be true ?Now,'must be true' means it has to satisfy all the possible plugin values taking one from each of the category i.e. positive fraction and integer and negative fraction and integer as per the given conditions. Whereas, for x>1 it does satisfy for all the possible values like x=3/2,4 etc. and the inequality holds good.So.how can we ignore the above case where the inequality clearly becomes false ?
_________________



Math Expert
Joined: 02 Sep 2009
Posts: 58380

Re: x/x<x. which of the following must be true about x ?
[#permalink]
Show Tags
28 Dec 2012, 05:04
debayan222 wrote: Bunuel wrote: OA for this question is B and it's not wrong.
Consider following: If \(x=5\), then which of the following must be true about \(x\): A. x=3 B. x^2=10 C. x<4 D. x=1 E. x>10
Answer is E (x>10), because as x=5 then it's more than 10.
Or: If \(1<x<10\), then which of the following must be true about \(x\): A. x=3 B. x^2=10 C. x<4 D. x=1 E. x<120
Again answer is E, because ANY \(x\) from \(1<x<10\) will be less than 120 so it's always true about the number from this range to say that it's less than 120.
The same with original question:
If \(1<x<0\) or \(x>1\), then which of the following must be true about \(x\): A. x>1 B. x>1 C. x<1 D. x=1 E. x^2>1
As \(1<x<0\) or \(x>1\) then ANY \(x\) from these ranges would satisfy \(x>1\). So B is always true.
\(x\) could be for example 1/2, 3/4, or 10 but no matter what \(x\) actually is it's IN ANY CASE more than 1. So we can say about \(x\) that it's more than 1.
On the other hand A says that \(x>1\), which is not always true as \(x\) could be 1/2 and 1/2 is not more than 1.
Hope it's clear.
Bunuel, As you've mentioned that we're to verify the range of x for which the given inequality holds good. So for x>1, x can have the value like 1/2. So in that case the inequality doesn't hold good for sure. Aren't we validating the inequality to be true ?Now,'must be true' means it has to satisfy all the possible plugin values taking one from each of the category i.e. positive fraction and integer and negative fraction and integer as per the given conditions. Whereas, for x>1 it does satisfy for all the possible values like x=3/2,4 etc. and the inequality holds good.So.how can we ignore the above case where the inequality clearly becomes false ? I think you don't understand what is given and what is asked. Given: 1<x<0 and x>1 (that's what x/x<x means). Now, the question asks which of the following MUST be true. You are saying: "so for x>1, x can have the value like 1/2." That's not correct: if 1<x<0 and x>1, then how x can be 1/2?
_________________



Manager
Joined: 22 Aug 2013
Posts: 73

x/x<x. which of the following must be true about x ?
[#permalink]
Show Tags
24 Mar 2014, 07:40
Hi Bunuel, Can you help clear the confusion with X = 1/2. Thanks.
_________________
Veritas Prep  650 MGMAT 1 590 MGMAT 2 640 (V48/Q31)
Please help the community by giving Kudos.



Math Expert
Joined: 02 Sep 2009
Posts: 58380

x/x<x. which of the following must be true about x ?
[#permalink]
Show Tags
24 Mar 2014, 07:51
seabhi wrote: Hi Bunuel, Can you help clear the confusion with X = 1/2.
Thanks. x/x<x, which of the following must be true about x ?A. x>1 B. x>1 C. x<1 D. x=1 E. x^2>1 We are given that \(\frac{x}{x}<x\) (this is a true inequality), so first of all we should find the ranges of \(x\) for which this inequality holds true. \(\frac{x}{x}< x\) multiply both sides of inequality by \(x\) (side note: we can safely do this as absolute value is nonnegative and in this case we know it's not zero too) > \(x<xx\) > \(x(x1)>0\): Either \(x>0\) and \(x1>0\), so \(x>1\) or \(x<1\) > \(x>1\); Or \(x<0\) and \(x1<0\), so \(1<x<1\) > \(1<x<0\). So we have that: \(1<x<0\) or \(x>1\). Note \(x\) is ONLY from these ranges. Option B says: \(x>1\) > ANY \(x\) from above two ranges would be more than 1, so B is always true. Answer: B.
_________________



Math Expert
Joined: 02 Sep 2009
Posts: 58380

Re: x/x<x. which of the following must be true about x ?
[#permalink]
Show Tags
02 Sep 2019, 22:36
christoph wrote: x/x<x. Which of the following must be true about x ? A. x > 1 B. x > 1 C. x < 1 D. x = 1 E. x^2 > 1 THE CORRECT ANSWER IS THERE IS NO DEBATE WHATSOEVER. PLEASE READ THE WHOLE DISCUSSION TO UNDERSTAND THE QUESTION BETTER.To understand the underline concept better practice other Trickiest Inequality Questions Type: Confusing Ranges.
_________________




Re: x/x<x. which of the following must be true about x ?
[#permalink]
02 Sep 2019, 22:36






