On the number line, the distance between x and y is greater than the

Question

On the number line, the distance between x and y is greater than the distance between x and z. Does z lie between x and y on the number line?

(1) xyz < 0
(2) xy < 0

Bunuel · Accepted Answer

On the number line, the distance between x and y is greater than the distance between x and z. Does z lie between x and y on the number line? The distance between x and y is greater than the distance between x and z , means that we can have one of the following four scenarios: A. y--------z--x (YES case); B. x--z--------y (YES case); C. y--------x--z (NO case); D. z--x--------y (NO case)' The question asks whether we have scenarios A or B ( z lies between x and y ). (1) xyz <0 --> either all three are negative or any two are positive and the third one is negative. If we place zero between y and z in case A (making y negative and x , z positive), then the answer would be YES but if we place zero between y and x in case C, then the answer would be NO. Not sufficient. (2) xy<0 --> x and y have opposite signs. The same here: We can place zero between y and x in case A and the answer would be YES but we can also place zero between y and x in case C and the answer would be NO. Not sufficient. (1)+(2) Both case A (answer YES) and case C (answer NO) satisfy the statements. Not sufficient. A. y----0----z--x (YES case) --> xyz<0 and xy<0 ; C. y----0----x--z (NO case) --> xyz<0 and xy<0 . Answer: E. Hope it's clear.

omerrauf · Answer

1. Statement 1 tells us that xyz<0 Which basically means that either all 3 are negative or one of them is negative. We can draw two scenarios of a number line where z is between x and y and where z is on the right of x and y on the left of x and maintain the condition that all three are negative. Hence Insufficient. 2. Statement 2 tells us that xy<0 Which basically means that either x is negative or y is negative. No statement about z so obviously insufficient. Now together we know that if either x or y are negative, and one of them is positive, z has to be positive. So again we draw two scenarios on the number line and we find that two cases are possible, one where z is in the middle and one where it is not. Hence both statements combined are insufficient as well. Answer. E .. I am attaching a diagram to illustrate. Number%20Line.jpg

mbaiseasy · Answer

Best technique is to draw and visualize their positions in the numberline...

1. xyz < 0
Try x and y and z as all negative...
<---(z)---x--(z)---y-----0------------>

Just this scenario is already giving us two possibilities...
INSUFFICIENT

2. xy < 0
This means x and y has opposite signs...

<----(z)---x--(z)--0-------y------>

Just this scenario is already giving us two possibilities...
INSUFFICIENT

Now, let us combine...
If x and y has opposite signs then for xyz to be negative z must be positive...

scenario 1: <---------x-----0-(z)-------y--------------> YES z is in between
scenario 2: <---------y-----0-----(z)-------x------(z)-------> NO z is not in between

STILL INSUFFICIENT

Answer: E

mohnish104 · Answer

Bunuel, I have a question. Among the 4 cases why are C & D a "no case".

Bunuel · Answer

Because in cases C and D z does not lie between x and y. Remember that the questions asks whether z lies between x and y on a number line.

Stoneface · Answer

Bunuel, couldn't it also be possible that the variables are arranged so x is between z and y? For example z->x->y, instead of only x->y->z? It's kind of an incidental point because I got it right, but I want to make sure I am figuring it up the proper way.

Also, when the statements xyz or xy, is that to say how the numbers are located with reference to zero, or is it saying to multiply the numbers?

Also, when the statements xyz or xy, is that to say how the numbers are located with reference to zero, or is it saying to multiply the numbers?

Bunuel · Answer

We know that  the distance between x and y is greater than the distance between x and z . This can happen in 4 ways, shown in my post. You can see there that x CAN be between z and y in cases C and D.

As for xyz it means x*y*z.

alwaysnewbie · Answer

Using (I) and (II) alone, it is easy to figure that each statement alone is not sufficient.

Combining (I) and (II), we have xyz < 0 and xy < 0, this implies that z is positive
(if z is negative then xyz is > 0 [since xy < 0 as per (II)] and xyz > 0 violates (I). Hence z cannot be negative).
When combining (I) and (II) we can take two cases
x is -ve or y is -ve [both cannot have the same sign as this violates (II)].

We will have the below 3 cases for x is -ve and y is -ve. No single solution exists and hence both together not sufficient. Answer is E.

Thanks

Attachments

z between x and y.jpg [ 47.42 KiB | Viewed 92403 times ]

anairamitch1804 · Answer

Scenario A ) where XYZ < 0.

2 positives 1 negative 
3 negatives.

For three negatives on the number the order can be z, x, y, 0...or x, z, y, 0.

So A is insufficient.

Scenario B) hwere XY < 0.

One negative one positive. So the order can go. x 0 z y...or z x 0 y. So B is insufficient.

Scenario A+B.

If X and Y are both of oppositie signs (XY<0)..then Z has to be postive in order for XYZ < 0.

So One Negative and two positives.

Order can be.....x 0 z y...or y 0 x z.

Thus E.

gary391 · Answer

Here is another way to look at the problem.

According to the question, the distance on x and y is greater than x and z, since we have x as the reference point for calculating the distance.

We can only have two cases.

Case 1 - When x is in the middle of y and z

Case 2 - When x is at the extreme end i.e. on one side.

Statement 1 and Statement 2 doesn't provide us the exact values of x,y,z, therefore, Answer is E

ScottTargetTestPrep · Answer

We are given that on the number line, the distance between x and y is greater than the distance between x and z. We need to determine whether z lies between x and y on the number line.
 
Statement One Alone:

xyz < 0
 
Using the information in statement one, we have two possible cases:

Case 1: Exactly one variable (either x, y, or z) is negative

Case 2: All three variables are negative.

Even with this information, we cannot determine whether z lies between x and y.
 
For example, for Case 1, if x = -1, y = 2, and z = 1, then z falls between x and y. However, for Case 2, if x = 1, y = 4, and z = -1, then z does not fall between x and y. Statement one alone is not sufficient. We can eliminate answer choices A and D.
 
Statement Two Alone:

xy < 0
 
Using the information from statement two, we know that exactly one of the values x or y is negative and the other is positive. However, without knowing anything about z, we cannot determine whether z falls between x and y. Statement two alone is not sufficient. We can eliminate answer choice B.
 
Statements One and Two Together:
 
From the information in statements one and two, we know that z must be positive and exactly one of the values x or y is negative. However, we still we cannot determine whether z falls between x and y or outside x and y.
 
For example, if x = -1, y = 2, and z = 1, then z falls between x and y. However, if x = 1, y = -2, and z = 2, then z does not fall between x and y. The two statements together are still not sufficient.
 
Answer: E

EMPOWERgmatRichC · Answer

Hi All,

We're told that, on a number line, the distance between X and Y is GREATER than the distance between X and Z. We're asked if Z is BETWEEN X and Y on the number line. This is a YES/NO question. This question can be solved in a number of different ways. You can use a combination of TESTing VALUES and Number Properties to get to the solution:

Fact 1: (X)(Y)(Z) < 0

This tells us that the three variables are either all negative OR 1 negative and 2 positives.

IF... 
X = 1 
Y = -2 
Z = 2 
Then the answer to the question is NO.

IF... 
X = 2 
Y = -2 
Z = 1 
Then the answer to the question is YES. 
Fact 1 is INSUFFICIENT

Fact 2: (X)(Y) < 0

This tells us that one variable is positive and the other is negative. Unfortunately it tells us NOTHING about Z. As it stands though, the TESTs that I did in Fact 1 fit Fact 2 as well....

IF... 
X = 1 
Y = -2 
Z = 2 
Then the answer to the question is NO.

IF... 
X = 2 
Y = -2 
Z = 1 
Then the answer to the question is YES. 
Fact 2 is INSUFFICIENT

Combined, we already have two TESTs that fit BOTH Facts and produce different answers (a NO and a YES), so there's no more work needed. 
Combined, INSUFFICIENT

Final Answer:  E

GMAT assassins aren't born, they're made, 
Rich

Jsound996 · Answer

From the information, we know that |x-y|>|x-z|, now we need to determine whether z is between x and y.

(1) xyz < 0
This tells us that all 3 of the values are negative (which could mean that z is in between x and y or not) or z is negative and x and y are positive
Insufficient

(2) xy < 0
This tells us that x and y have opposite signs, but tells nothing about z
Insufficient

1+2
Because we know that either x or y has to be negative (from statement 2), that means Z HAS to be negative. But Z could be greater than X (which would give a yes), or Z could be is less than X (which would give a no)

Both Statements are insufficient.
Answer is E

minustark · Answer

(1) xyz < 0 , atleast one or all of the 3 is negative.Too broad to define. it can be like (x = -4, z = -1, y = -10) (x = 2, y = 6, z =-1)(z is the rightmost and leftmost respectively in the number line). or ( x= 6, y = -1, z = 1)(here z is in the middle of x and y). Not sufficient.

(2) xy < 0. either x or y has to be negative. No information about z. Not sufficient.

Together, lets take x = 5, y = -2, z = 6 ( z is the rightmost), or x = -8, y = 2 and z = -7 (z in the middle). so Not sufficient.

E is the answer.

RashedVai · Answer

On the number line the distance bet x & y is greater than the distance between x & z.
^^ given this statement, the number line can appear in one of exactly four ways:

case 1:--------------------x------z-------y---------
case 2: -------------z------x--------------y---------
case 3: -----y--------------x------z-----------------
case 4: -----y------z-------x------------------------

cases 1 and 4 are "yes" to the question; cases 2 and 3 are "no". since the GOAL is to TRY FOR "INSUFFICIENT" (as in just about any non-algebraic DS problem), you should try to get one instance of case 1 or 4, and one instance of case 2 or 3.

(1) xyz<0
^^ you can make any of the four cases with 3 negative numbers, so this statement is insufficient (you don't even have to consider the cases in which some of them are positive).
e.g.
x = -3, z = -2, y = -1 --> case 1 ("yes" to the question)
z = -4, x = -3, y = -1 --> case 2 ("no" to the question)

(2) xy<0
^^ again, easy to get any of the three cases -- x and y just have to be one positive and one negative, and z can be, well, anything at all.
e.g.
x = -2, z = 1, y = 2 --> case 1 ("yes" to the question)
z = -3, x = -2, y = 2 --> case 2 ("no" to the question)

together:
if you have both statements, then you know:
x and y are one positive, one negative;
z is positive.
you can still get both answers:
x = -2, z = 1, y = 2 --> case 1 ("yes" to the question)
y = -2, x = 2, z = 3 --> case 2 ("no" to the question)
still insufficient.

answer = (e)

MHIKER · Answer

(1)Option (a) ----z---0-x-------------y--- = xyz<0; Z IS OUTSIDE X AND Y
 Option (b) ------x--0--z-----------y---- =xyz<0; Z IS IN BETWEEN X AND Y
 Option (c) ------x---z--------y----0---- =xyz<0; Z IS IN BETWEEN X AND Y
 Option (d)-------z---x--------y----0---- =xyz<0; Z IS OUTSIDE X AND Y
 
INSUFFICIENT

(2) Option (A) ------x--------0-------y-= xy<0; Z could be anywhere on the number line. INSUFFICIENT

Using both the information. 
No additional information is available to give a confirm point for Z.

Ans. E.

vaibhav1221 · Answer

Bunuel

Can I say that because the question talks about only distance/magnitude and not signs and the options talk about only signs and not distance the answer would be E?

TargetMBA007 · Answer

Bunuel

Source: Gmat-Prep

bumpbot · Answer

Automated notice from GMAT Club BumpBot: 

A member just gave Kudos to this thread, showing it’s still useful. I’ve bumped it to the top so more people can benefit. Feel free to add your own questions or solutions.

 This post was generated automatically.

On the number line, the distance between x and y is greater than the

Prep Toolkit

Top 5 GMAT Debrief Videos

615 to 715 in 15 Days (Ria's Strategies)

More than Quant/Verbal Abilities: Speed vs. Accuracy

745 with Only Self-Prep and GMAT Club

From 555 to 765: 210-point Improvement

Perfect 805 Score Debrief by Julia

My Rewards

GMAT Data Sufficiency (DS) Questions

On the number line, the distance between x and y is greater than the

Prep Toolkit

615 to 715 in 15 Days (Ria's Strategies)

More than Quant/Verbal Abilities: Speed vs. Accuracy

745 with Only Self-Prep and GMAT Club

From 555 to 765: 210-point Improvement

Perfect 805 Score Debrief by Julia

My Rewards