GMAT Question of the Day - Daily to your Mailbox; hard ones only

It is currently 15 Nov 2018, 04:52

ISB R1 results on Nov 15:

Join Chat Room for Live Updates


Close

GMAT Club Daily Prep

Thank you for using the timer - this advanced tool can estimate your performance and suggest more practice questions. We have subscribed you to Daily Prep Questions via email.

Customized
for You

we will pick new questions that match your level based on your Timer History

Track
Your Progress

every week, we’ll send you an estimated GMAT score based on your performance

Practice
Pays

we will pick new questions that match your level based on your Timer History

Not interested in getting valuable practice questions and articles delivered to your email? No problem, unsubscribe here.

Close

Request Expert Reply

Confirm Cancel
Events & Promotions in November
PrevNext
SuMoTuWeThFrSa
28293031123
45678910
11121314151617
18192021222324
2526272829301
Open Detailed Calendar
  • Free GMAT Strategy Webinar

     November 17, 2018

     November 17, 2018

     07:00 AM PST

     09:00 AM PST

    Nov. 17, 7 AM PST. Aiming to score 760+? Attend this FREE session to learn how to Define your GMAT Strategy, Create your Study Plan and Master the Core Skills to excel on the GMAT.
  • GMATbuster's Weekly GMAT Quant Quiz # 9

     November 17, 2018

     November 17, 2018

     09:00 AM PST

     11:00 AM PST

    Join the Quiz Saturday November 17th, 9 AM PST. The Quiz will last approximately 2 hours. Make sure you are on time or you will be at a disadvantage.

M31-38

  new topic post reply Question banks Downloads My Bookmarks Reviews Important topics  
Author Message
TAGS:

Hide Tags

Math Expert
User avatar
V
Joined: 02 Sep 2009
Posts: 50608
M31-38  [#permalink]

Show Tags

New post 20 Jun 2015, 09:17
00:00
A
B
C
D
E

Difficulty:

  35% (medium)

Question Stats:

77% (00:36) correct 23% (00:30) wrong based on 47 sessions

HideShow timer Statistics

Image

On the number line shown above, the tick marks are equally spaced. Which of the following statements about the numbers \(x\), \(y\), and \(z\) must be true?

I. \(xyz < 0\)

II. \(x + z = y\)

III. \(z(y - x) > 0\)


A. I only
B. II only
C. III only
D. I and III only
E. I, II and III

_________________

New to the Math Forum?
Please read this: Ultimate GMAT Quantitative Megathread | All You Need for Quant | PLEASE READ AND FOLLOW: 12 Rules for Posting!!!

Resources:
GMAT Math Book | Triangles | Polygons | Coordinate Geometry | Factorials | Circles | Number Theory | Remainders; 8. Overlapping Sets | PDF of Math Book; 10. Remainders | GMAT Prep Software Analysis | SEVEN SAMURAI OF 2012 (BEST DISCUSSIONS) | Tricky questions from previous years.

Collection of Questions:
PS: 1. Tough and Tricky questions; 2. Hard questions; 3. Hard questions part 2; 4. Standard deviation; 5. Tough Problem Solving Questions With Solutions; 6. Probability and Combinations Questions With Solutions; 7 Tough and tricky exponents and roots questions; 8 12 Easy Pieces (or not?); 9 Bakers' Dozen; 10 Algebra set. ,11 Mixed Questions, 12 Fresh Meat

DS: 1. DS tough questions; 2. DS tough questions part 2; 3. DS tough questions part 3; 4. DS Standard deviation; 5. Inequalities; 6. 700+ GMAT Data Sufficiency Questions With Explanations; 7 Tough and tricky exponents and roots questions; 8 The Discreet Charm of the DS; 9 Devil's Dozen!!!; 10 Number Properties set., 11 New DS set.


What are GMAT Club Tests?
Extra-hard Quant Tests with Brilliant Analytics

Math Expert
User avatar
V
Joined: 02 Sep 2009
Posts: 50608
Re M31-38  [#permalink]

Show Tags

New post 20 Jun 2015, 09:17
Official Solution:


Image

On the number line shown above, the tick marks are equally spaced. Which of the following statements about the numbers \(x\), \(y\), and \(z\) must be true?

I. \(xyz < 0\)

II. \(x + z = y\)

III. \(z(y - x) > 0\)


A. I only
B. II only
C. III only
D. I and III only
E. I, II and III

The tick marks are equally spaced, so let's assign such values to the variables that satisfy this requirement. Say \(x = -1\), \(y = 1\) and \(z = 2\). We can see that all three options are true.

Answer: E
_________________

New to the Math Forum?
Please read this: Ultimate GMAT Quantitative Megathread | All You Need for Quant | PLEASE READ AND FOLLOW: 12 Rules for Posting!!!

Resources:
GMAT Math Book | Triangles | Polygons | Coordinate Geometry | Factorials | Circles | Number Theory | Remainders; 8. Overlapping Sets | PDF of Math Book; 10. Remainders | GMAT Prep Software Analysis | SEVEN SAMURAI OF 2012 (BEST DISCUSSIONS) | Tricky questions from previous years.

Collection of Questions:
PS: 1. Tough and Tricky questions; 2. Hard questions; 3. Hard questions part 2; 4. Standard deviation; 5. Tough Problem Solving Questions With Solutions; 6. Probability and Combinations Questions With Solutions; 7 Tough and tricky exponents and roots questions; 8 12 Easy Pieces (or not?); 9 Bakers' Dozen; 10 Algebra set. ,11 Mixed Questions, 12 Fresh Meat

DS: 1. DS tough questions; 2. DS tough questions part 2; 3. DS tough questions part 3; 4. DS Standard deviation; 5. Inequalities; 6. 700+ GMAT Data Sufficiency Questions With Explanations; 7 Tough and tricky exponents and roots questions; 8 The Discreet Charm of the DS; 9 Devil's Dozen!!!; 10 Number Properties set., 11 New DS set.


What are GMAT Club Tests?
Extra-hard Quant Tests with Brilliant Analytics

Intern
Intern
avatar
B
Joined: 29 Nov 2014
Posts: 22
Re: M31-38  [#permalink]

Show Tags

New post 27 Oct 2015, 11:12
I think this is a high-quality question and I don't agree with the explanation. -1, 1 and 2 are not equally spaced. -1, 1 and 3 would be equally spaced. So the answer should be I and III only.
Current Student
User avatar
B
Joined: 18 Jun 2015
Posts: 41
Reviews Badge
Re: M31-38  [#permalink]

Show Tags

New post 10 Sep 2016, 07:36
1
The question clearly says the tick mark are equaly spaced. "0" is one of the tick mark. Hence the origiona explanation is correct. al three options are feasibe and correct.
Intern
Intern
avatar
Joined: 20 Sep 2016
Posts: 3
Location: Spain
GMAT 1: 740 Q50 V40
GPA: 3
Re: M31-38  [#permalink]

Show Tags

New post 15 Jan 2017, 04:59
Hi,

Should we assume that the positive numbers go from zero to right and the negatives from zero to left?

In my opinion it is not clear the direction in which numbers increase. For example, 1, 0, -1, -2 could be possible and then statement 1 wouldn't be true.

Thank you!
Math Expert
User avatar
V
Joined: 02 Sep 2009
Posts: 50608
Re: M31-38  [#permalink]

Show Tags

New post 15 Jan 2017, 08:08
nachobs wrote:
Hi,

Should we assume that the positive numbers go from zero to right and the negatives from zero to left?

In my opinion it is not clear the direction in which numbers increase. For example, 1, 0, -1, -2 could be possible and then statement 1 wouldn't be true.

Thank you!


Positive numbers are numbers that are greater than 0 and are to the right of 0 on the number line.
Negative numbers are numbers that are less than 0 and are to the left of 0 on the number line.

0 is neither positive nor negative.
_________________

New to the Math Forum?
Please read this: Ultimate GMAT Quantitative Megathread | All You Need for Quant | PLEASE READ AND FOLLOW: 12 Rules for Posting!!!

Resources:
GMAT Math Book | Triangles | Polygons | Coordinate Geometry | Factorials | Circles | Number Theory | Remainders; 8. Overlapping Sets | PDF of Math Book; 10. Remainders | GMAT Prep Software Analysis | SEVEN SAMURAI OF 2012 (BEST DISCUSSIONS) | Tricky questions from previous years.

Collection of Questions:
PS: 1. Tough and Tricky questions; 2. Hard questions; 3. Hard questions part 2; 4. Standard deviation; 5. Tough Problem Solving Questions With Solutions; 6. Probability and Combinations Questions With Solutions; 7 Tough and tricky exponents and roots questions; 8 12 Easy Pieces (or not?); 9 Bakers' Dozen; 10 Algebra set. ,11 Mixed Questions, 12 Fresh Meat

DS: 1. DS tough questions; 2. DS tough questions part 2; 3. DS tough questions part 3; 4. DS Standard deviation; 5. Inequalities; 6. 700+ GMAT Data Sufficiency Questions With Explanations; 7 Tough and tricky exponents and roots questions; 8 The Discreet Charm of the DS; 9 Devil's Dozen!!!; 10 Number Properties set., 11 New DS set.


What are GMAT Club Tests?
Extra-hard Quant Tests with Brilliant Analytics

SVP
SVP
User avatar
D
Joined: 26 Mar 2013
Posts: 1879
Reviews Badge CAT Tests
Re: M31-38  [#permalink]

Show Tags

New post 16 Jan 2017, 02:01
Image

On the number line shown above, the tick marks are equally spaced. Which of the following statements about the numbers \(x\), \(y\), and \(z\) must be true?

I. \(xyz < 0\)

II. \(x + z = y\)

III. \(z(y - x) > 0\)

Let x= -2 , y=2 and z=4

I. \(xyz < 0\)

-2 *2 *4 = -16 <0 .........True

II. \(x + z = y\)

-2+ 4=2 =y..........True

III. \(z(y - x) > 0\)

4 [2 - (-2)]= 4 *4 =16>0.............True

Answer: E
Manager
Manager
avatar
S
Joined: 23 Sep 2016
Posts: 218
Premium Member Reviews Badge
Re: M31-38  [#permalink]

Show Tags

New post 21 Mar 2018, 23:24
1
Bunuel wrote:
Image

On the number line shown above, the tick marks are equally spaced. Which of the following statements about the numbers \(x\), \(y\), and \(z\) must be true?

I. \(xyz < 0\)

II. \(x + z = y\)

III. \(z(y - x) > 0\)


A. I only
B. II only
C. III only
D. I and III only
E. I, II and III

sorry, but i think this one also have same problem please edit this one also.
Math Expert
User avatar
V
Joined: 02 Sep 2009
Posts: 50608
Re: M31-38  [#permalink]

Show Tags

New post 22 Mar 2018, 00:38
rishabhmishra wrote:
Bunuel wrote:
Image

On the number line shown above, the tick marks are equally spaced. Which of the following statements about the numbers \(x\), \(y\), and \(z\) must be true?

I. \(xyz < 0\)

II. \(x + z = y\)

III. \(z(y - x) > 0\)


A. I only
B. II only
C. III only
D. I and III only
E. I, II and III

sorry, but i think this one also have same problem please edit this one also.

_______________
Edited. Thank you.
_________________

New to the Math Forum?
Please read this: Ultimate GMAT Quantitative Megathread | All You Need for Quant | PLEASE READ AND FOLLOW: 12 Rules for Posting!!!

Resources:
GMAT Math Book | Triangles | Polygons | Coordinate Geometry | Factorials | Circles | Number Theory | Remainders; 8. Overlapping Sets | PDF of Math Book; 10. Remainders | GMAT Prep Software Analysis | SEVEN SAMURAI OF 2012 (BEST DISCUSSIONS) | Tricky questions from previous years.

Collection of Questions:
PS: 1. Tough and Tricky questions; 2. Hard questions; 3. Hard questions part 2; 4. Standard deviation; 5. Tough Problem Solving Questions With Solutions; 6. Probability and Combinations Questions With Solutions; 7 Tough and tricky exponents and roots questions; 8 12 Easy Pieces (or not?); 9 Bakers' Dozen; 10 Algebra set. ,11 Mixed Questions, 12 Fresh Meat

DS: 1. DS tough questions; 2. DS tough questions part 2; 3. DS tough questions part 3; 4. DS Standard deviation; 5. Inequalities; 6. 700+ GMAT Data Sufficiency Questions With Explanations; 7 Tough and tricky exponents and roots questions; 8 The Discreet Charm of the DS; 9 Devil's Dozen!!!; 10 Number Properties set., 11 New DS set.


What are GMAT Club Tests?
Extra-hard Quant Tests with Brilliant Analytics

Manager
Manager
avatar
B
Status: Turning my handicaps into assets
Joined: 09 Apr 2017
Posts: 123
M31-38  [#permalink]

Show Tags

New post 15 May 2018, 05:43
I think in MUST BE question it’s risky to check with only one set of numbers since we have to be assured that condition works for all the numbers. Below is how I solved this question:

First, looking at the number line we can infer that since it is evenly spaced set absolute value of x is equal to the absolute value of y, or in other words y=-x, where x<0. For example, if x=-3, then y= -(-3)=3.

Now, let’s analyze the options.

I. xyz<0 - Must be true, since x is negative, while others are positive.

II. x+z=y - to be sure for this one, I’ve checked two sets: -1,1,2 and -2,2,4. Both yields true. So, it must be true

III. z(y−x)>0- here both multiples (z and (y-x)) must be positive or negative. Now, since z is positive, (y-x) must be positive. Since y is positive and x is negative, the answer must be positive i.e. 2- (-1)=3>0.

Hence, all of them MUST be true. Answer is E.
_________________

If time was on my side, I'd still have none to waste......

GMAT Club Bot
M31-38 &nbs [#permalink] 15 May 2018, 05:43
Display posts from previous: Sort by

M31-38

  new topic post reply Question banks Downloads My Bookmarks Reviews Important topics  

Moderators: chetan2u, Bunuel



Copyright

GMAT Club MBA Forum Home| About| Terms and Conditions and Privacy Policy| GMAT Club Rules| Contact| Sitemap

Powered by phpBB © phpBB Group | Emoji artwork provided by EmojiOne

Kindly note that the GMAT® test is a registered trademark of the Graduate Management Admission Council®, and this site has neither been reviewed nor endorsed by GMAC®.