DS ques . Pls explain.

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Source: — Data Sufficiency |

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by gig92 » Fri Jul 23, 2010 4:45 am
If [x] denotes the greatest integer less than or equal to x, is [x] = 0?

(1) 5x + 1 = 3 + 2x
(2) 0 < x < 1

OA D

Pls. explain wrt option (2).


REPLY:

According to option 2) X can have any "real" value between 0 and 1. We are given that [X] is less than or equal to x, thus integer value less than 1 is 0.
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by r2kins » Fri Jul 23, 2010 4:52 am
gig92 wrote:If [x] denotes the greatest integer less than or equal to x, is [x] = 0?

(1) 5x + 1 = 3 + 2x
(2) 0 < x < 1

OA D

Pls. explain wrt option (2).


REPLY:

According to option 2) X can have any "real" value between 0 and 1. We are given that [X] is less than or equal to x, thus integer value less than 1 is 0.
Thanks gig92, but the solution mentioned that the question can be restated as - 0 <= x < 1. I dont understand where this came from?

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by outreach » Fri Jul 23, 2010 5:19 am
[x]<=x
if x=0,then it should have value between 0 and 1(x is an integer). if x greater than 1, then x cannot equal 0
r2kins wrote:
gig92 wrote:If [x] denotes the greatest integer less than or equal to x, is [x] = 0?

(1) 5x + 1 = 3 + 2x
(2) 0 < x < 1

OA D

Pls. explain wrt option (2).


REPLY:

According to option 2) X can have any "real" value between 0 and 1. We are given that [X] is less than or equal to x, thus integer value less than 1 is 0.
Thanks gig92, but the solution mentioned that the question can be restated as - 0 <= x < 1. I dont understand where this came from?
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by aloneontheedge » Sat Jul 24, 2010 12:01 pm
r2kins wrote:
gig92 wrote:If [x] denotes the greatest integer less than or equal to x, is [x] = 0?

(1) 5x + 1 = 3 + 2x
(2) 0 < x < 1

OA D

Pls. explain wrt option (2).


REPLY:

According to option 2) X can have any "real" value between 0 and 1. We are given that [X] is less than or equal to x, thus integer value less than 1 is 0.
Thanks gig92, but the solution mentioned that the question can be restated as - 0 <= x < 1. I dont understand where this came from?
This is how greatest integer is calculated
[1.4] = 1,[4]=4,[3.9]=3,[-5.6]=-5
hope this helps

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by saloniarora » Fri May 04, 2012 7:50 am
I might be missing something obvious here but will the answer still be 0 if x is .99(recurring)?

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by aneesh.kg » Fri May 04, 2012 8:02 pm
Saloni,

when x = 0.9999999999.., it is still 0.0000000000..1 lesser than 1.

What are the integers smaller than 0.9999999999.. ?
0, -1, -2,..
What is the greatest integer among these?
0

So, the greatest integer smaller or equal to x is 0.
i.e. [0.9999999999..] = 0
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by ronnie1985 » Sat May 05, 2012 9:46 am
Data sufficiency questions are all about solvable questions. the answer to the question can be yes or no or may be. "May be" is "not sufficient". In this case if we can answer yes or no we are definite in our answer.

S1. [x] = -1 m=not equal to 0
Sufficient

S2. [x] = 0, sufficient

(D) is answer.
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by ronnie1985 » Sat May 05, 2012 9:51 am
saloniarora wrote:I might be missing something obvious here but will the answer still be 0 if x is .99(recurring)?
Yes as 0.9 bar is still less than 1, though infinitesimally. The nearest integer less than 0.9 bar is zero.
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