If 2

Question

If  2 < x < 5  and  3 < y < 5 , which of the following best describes  x – y?

(A)  –3 < x – y < 2

(B)  –3 < x – y < 5

(C)  0 < x – y < 2

(D)  3 < x – y < 5

(E)  2 < x – y < 5

Source:  Nova GMAT

IanStewart · Answer

The wording is bizarre, because it's not a CR question - the right answer doesn't "best describe" x-y; it is the set of all possible values of x-y. We get the largest value of x-y when x is largest and y is smallest, so the largest value of x-y is just less than 5-3 = 2. We get the smallest value of x-y when x is smallest and y is largest, so the smallest possible value of x-y is just greater than 2-5 = -3. So -3 < x-y < 2.

Archit3110 · Answer

given
  2 < x < 5  and  3 < y < 5 
so x-y ; 2-5 <x-y<5-3 ; -3<x-y<2
IMO A

aggvipul · Answer

lo 
I have one doubt, what if we plot both x and y on number line. This then results in 
X = 2  --- --------------- 5
Y = ----3 -------------- 5
that means, 2<x-y<3 ?
Pls explain, why is this logic wrong 
 SajjadAhmad

IanStewart · Answer

Because that's not how subtraction works. If you try using your number line method when x = 10 and y = 4, you'll find that x-y doesn't exist, but x-y = 6 in that case.

I think you're answering a different question -- you're imagining X is the set of numbers between 2 and 5, and Y is the set of numbers between 3 and 5, and working out what set you'd get when you remove the values in set Y from the set X. In this question, x and y are not sets, they're just numbers, and the subtraction in the question is ordinary subtraction (we aren't subtracting one set from another).

Kinshook · Answer

Asked: If  2 < x < 5  and  3 < y < 5 , which of the following best describes  x – y?

2<x<5 (1) 
3<y<5
-5<-y<-3 (2)

(1) + (2)
-3<x-y<2

IMO A

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If 2 < x < 5 and 3 < y < 5, which of the following best describes x –

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