Modulus PS

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by kanwar86 » Sun Dec 04, 2011 4:34 am
kanwar86 wrote:
Stuart Kovinsky wrote:
satishchandra wrote:If x/lxl<x, which of the following must be true about x
(Note: Read lxl as modulus x)

A) x>1
B) x>-1
C) lxl<1
D) lxl = 1
E) lxl^2 > 1
The question is NOT asking us "which of the following (in)equations defines all possible values of x"; it's simply asking us which of the following MUST be true given the constraint provided. Accordingly, even though (b) contains some numbers outside the range, it MUST be true that x is greater than -1.
Wow! That was enlightening and a good example of how doubts can be cleared by such healthy discussions. Thanks for bringing this problem on the forum.

Cheers team BTG!
However, a problem just like the one we discussed is coming to my mind.
If (x-3)(x+2)>0; which of the following must be true about x.
1) x>3
2)-2<x<3
3)-inf<x<inf
What will be your answer in this case?
There is no OA. This question is merely for the purpose of discussion so as to understand the question stem. Kindly share your views.
Regards

Kanwar

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by satishchandra » Sun Dec 04, 2011 6:52 am
However, a problem just like the one we discussed is coming to my mind.
If (x-3)(x+2)>0; which of the following must be true about x.
1) x>3
2)-2<x<3
3)-inf<x<inf
What will be your answer in this case?
There is no OA. This question is merely for the purpose of discussion so as to understand the question stem. Kindly share your views.
Good that you framed some similar question.
Must be true about x is 3)-inf<x<inf
However, x<-2 & x>3 is the solution for the equation (x-3)(x+2)>0