Author 
Message 
TAGS:

Hide Tags

Manager
Joined: 31 Oct 2011
Posts: 211

If it is true that x>2 and x <7, which of the following must be true?
[#permalink]
Show Tags
14 Mar 2012, 14:24
Question Stats:
58% (00:50) correct 42% (00:59) wrong based on 1269 sessions
HideShow timer Statistics
If it is true that x > 2 and x < 7, which of the following must be true? A. x > 2 B. x > 7 C. x< 2 D. 7 < x < 2 E. none of the above.
Official Answer and Stats are available only to registered users. Register/ Login.




Math Expert
Joined: 02 Sep 2009
Posts: 61544

Re: If it is true that x>2 and x <7, which of the following must be true?
[#permalink]
Show Tags
29 Jun 2012, 06:52
kuttingchai wrote: Bunuel what is the reason B must be true ??? the range is 2<x<7 A. x > 2  no because x can be between 2<x<2 B. x > 7  the answer is true, is it because the values of x are always >7 C. x< 2  no because x can be between 2<x<7 D. 7 < x < 2  no beacuse x can be between 7<x<2 ???? E. none of the above.  i actually went for E answer choicein the another problem we had similar situation ANY x from the ranges 1<x<0 and x>1 will definitely be more the 1. I didnot understood the reason there as well??? ifxxxwhichofthefollowingmustbetrueaboutx68886.htmlOption D is not correct since x could be 2<x<7. Otherwise your reasoning is correct. We are given that \(2<x<7\). The question is which of the following is true about \(x\)? \(x>7\) is true about \(x\), because as \(x\) is more than 2 then it's definitely more than 7. To elaborate more. Question uses the same logic as in the examples below: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. Or: 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 for example A is not always true as it 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.
_________________




Math Expert
Joined: 02 Sep 2009
Posts: 61544

Re: If it is true that x>2 and x <7, which of the following must be true?
[#permalink]
Show Tags
14 Mar 2012, 14:48
eybrj2 wrote: If it is true that x > 2 and x <7, which of the following must be true?
A. x > 2 B. x > 7 C. x< 2 D. 7 < x < 2 E. none of the above. Given: 2<x<7. Now, any x from this true range is more than 7, so x>7 must be true. Answer: B.
_________________



Manager
Joined: 28 Jul 2011
Posts: 153

Re: If it is true that x>2 and x <7, which of the following must be true?
[#permalink]
Show Tags
29 Jun 2012, 06:19
Bunuel what is the reason B must be true ??? the range is 2<x<7 A. x > 2  no because x can be between 2<x<2 B. x > 7  the answer is true, is it because the values of x are always >7 C. x< 2  no because x can be between 2<x<7 D. 7 < x < 2  no beacuse x can be between 7<x<2 ???? E. none of the above.  i actually went for E answer choice in the another problem we had similar situation ANY x from the ranges 1<x<0 and x>1 will definitely be more the 1. I didnot understood the reason there as well??? ifxxxwhichofthefollowingmustbetrueaboutx68886.html



Manager
Joined: 28 Sep 2011
Posts: 56
Location: United States
GMAT 1: 520 Q34 V27 GMAT 3: 690 Q47 V38
GPA: 3.01
WE: Information Technology (Commercial Banking)

Re: If it is true that x>2 and x <7, which of the following must be true?
[#permalink]
Show Tags
29 Jun 2012, 09:24
Bunuel, what difficulty would you say this problem is? 600700 sounds awfully high, I was putting it more in the mid 500's.



Math Expert
Joined: 02 Sep 2009
Posts: 61544

Re: If it is true that x>2 and x <7, which of the following must be true?
[#permalink]
Show Tags
29 Jun 2012, 10:01
ashish8 wrote: Bunuel, what difficulty would you say this problem is? 600700 sounds awfully high, I was putting it more in the mid 500's. I'd say the difficulty level is ~600.
_________________



EMPOWERgmat Instructor
Status: GMAT Assassin/CoFounder
Affiliations: EMPOWERgmat
Joined: 19 Dec 2014
Posts: 16169
Location: United States (CA)

Re: If it is true that x>2 and x <7, which of the following must be true?
[#permalink]
Show Tags
11 Jan 2015, 23:59
Hi All, This question has a real "quirky" design to it. To get the correct answer, you have to focus on the limitations given in the prompt. Consider ALL of the possibilities for X IN THE PROMPT, then select the answer that is TRUE for all of THOSE values. To get you thinking in the proper way, consider the following.... If you KNOW that X = 0, is it true that X > 1? Yes. If you KNOW that 3 > X > 0, is it true that X > 10? Yes. Notice the pattern in the logic. I'm NOT presenting the idea that X is everything greater than 10. I'm just asking if, given the limitations, that the statement is TRUE. As it stands, this type of "quirky design" doesn't show up on Test Day all that often, but plenty of standard questions WILL ask you for "what must be true?" GMAT assassins aren't born, they're made, Rich
_________________
Contact Rich at: Rich.C@empowergmat.comThe Course Used By GMAT Club Moderators To Earn 750+ souvik101990 Score: 760 Q50 V42 ★★★★★ ENGRTOMBA2018 Score: 750 Q49 V44 ★★★★★



Intern
Joined: 26 Feb 2015
Posts: 5

Re: If it is true that x>2 and x <7, which of the following must be true?
[#permalink]
Show Tags
26 Feb 2016, 17:43
Brunel need your Help on this....
How can we say that option (B) X > 7 is correct because we are limited by X<7 and so our answer X>7 could even yield an answer of X=8,9,..... (which is not correct answer/range)
Hence I selected option (E)



CEO
Joined: 20 Mar 2014
Posts: 2538
Concentration: Finance, Strategy
GMAT 1: 750 Q49 V44
GPA: 3.7
WE: Engineering (Aerospace and Defense)

Re: If it is true that x>2 and x <7, which of the following must be true?
[#permalink]
Show Tags
26 Feb 2016, 18:23
ojas wrote: Brunel need your Help on this....
How can we say that option (B) X > 7 is correct because we are limited by X<7 and so our answer X>7 could even yield an answer of X=8,9,..... (which is not correct answer/range)
Hence I selected option (E) You are neglecting the fact that when we say 2<x<7, all these values ARE >7. You pick any value in this range (2<x<7) and you can very well say that x>7. This isnt the case with options A,C and D. Think of it this way. If I ask you to pick 1 number from 2<x<7, will it be >7? The answer is ALWAYS YES. This is the reason why B is the correct answer. It is a tricky question. Hope this helps.



Intern
Joined: 26 Feb 2015
Posts: 5

Re: If it is true that x>2 and x <7, which of the following must be true?
[#permalink]
Show Tags
28 Feb 2016, 16:00
Engr2012 I understood that, but we should have been picking that option if we would have no other option to select for. But in this case we have an option (E) none of the above, which can very well supersede the option for X>7. Please let me know if I am still missing on something else here.



CEO
Joined: 20 Mar 2014
Posts: 2538
Concentration: Finance, Strategy
GMAT 1: 750 Q49 V44
GPA: 3.7
WE: Engineering (Aerospace and Defense)

Re: If it is true that x>2 and x <7, which of the following must be true?
[#permalink]
Show Tags
28 Feb 2016, 16:50
ojas wrote: Engr2012 I understood that, but we should have been picking that option if we would have no other option to select for. But in this case we have an option (E) none of the above, which can very well supersede the option for X>7. Please let me know if I am still missing on something else here. In this particular question and for that matter for all must be true questions, you can only be sure of your answer if you can quote 1 example that will negate the given options. For this question, (B) was a clear winner. Any number falling in the range 2<x<7 will always be true for x>7. There is no example of a number that lies in the range 2<x<7 that does not satisfy x>7. Had there been a single case of such a number, E would have been the correct answer. Hope this helps.



Math Expert
Joined: 02 Sep 2009
Posts: 61544

Re: If it is true that x>2 and x <7, which of the following must be true?
[#permalink]
Show Tags
25 Dec 2017, 19:54
eybrj2 wrote: If it is true that x > 2 and x <7, which of the following must be true?
A. x > 2 B. x > 7 C. x< 2 D. 7 < x < 2 E. none of the above. Check other similar questions from Trickiest Inequality Questions Type: Confusing Ranges (part of our Special Questions Directory).
_________________



NonHuman User
Joined: 09 Sep 2013
Posts: 14162

Re: If it is true that x>2 and x <7, which of the following must be true?
[#permalink]
Show Tags
28 Jan 2019, 20:58
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.
_________________




Re: If it is true that x>2 and x <7, which of the following must be true?
[#permalink]
28 Jan 2019, 20:58






