Last visit was: 19 Nov 2025, 07:57 It is currently 19 Nov 2025, 07:57
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
User avatar
Bunuel
User avatar
Math Expert
Joined: 02 Sep 2009
Last visit: 19 Nov 2025
Posts: 105,389
Own Kudos:
Given Kudos: 99,977
Products:
Expert
Expert reply
Active GMAT Club Expert! Tag them with @ followed by their username for a faster response.
Posts: 105,389
Kudos: 778,259
 [142]
10
Kudos
Add Kudos
130
Bookmarks
Bookmark this Post
Most Helpful Reply
User avatar
Bunuel
User avatar
Math Expert
Joined: 02 Sep 2009
Last visit: 19 Nov 2025
Posts: 105,389
Own Kudos:
Given Kudos: 99,977
Products:
Expert
Expert reply
Active GMAT Club Expert! Tag them with @ followed by their username for a faster response.
Posts: 105,389
Kudos: 778,259
 [34]
15
Kudos
Add Kudos
19
Bookmarks
Bookmark this Post
User avatar
SOURH7WK
Joined: 15 Jun 2010
Last visit: 03 Aug 2022
Posts: 241
Own Kudos:
1,278
 [22]
Given Kudos: 50
Concentration: Marketing
GPA: 3.2
WE 1: 7 Yrs in Automobile (Commercial Vehicle industry)
Products:
16
Kudos
Add Kudos
6
Bookmarks
Bookmark this Post
General Discussion
User avatar
Bunuel
User avatar
Math Expert
Joined: 02 Sep 2009
Last visit: 19 Nov 2025
Posts: 105,389
Own Kudos:
778,259
 [4]
Given Kudos: 99,977
Products:
Expert
Expert reply
Active GMAT Club Expert! Tag them with @ followed by their username for a faster response.
Posts: 105,389
Kudos: 778,259
 [4]
4
Kudos
Add Kudos
Bookmarks
Bookmark this Post
PiyushK
Hi Bunuel,

I have a doubt, as per this thread D is the correct answer.
I calculated the range of x as -1<x<3, further option D says :
D. Number of distinct positive factors of x+2 is a prime number
for x=0 x+2 = 2 => distinct positive factors are 1 and 2
for x=1 x+2 = 3 => distinct positive factors are 1 and 3
for x=2 x+2 = 4 => distinct positive factors are 1 and 2

2,3 are prime numbers but 1 is not a prime number as per rule/definition.

Therefor I think D is also not a well articulated option.

Could you please share your opinion on this.

Regards,
PiyushK

Subject: If x is an integer and |1-x|<2 then which of the following

Bunuel
sanjoo
If x is an integer and |1−x|<2 then which of the following must be true?

A) x is not a prime number
B) x^2+x is not a prime number
C) x is positive
D) Number of distinct positive factors of x+2 is a prime number
E) x is not a multiple of an odd prime number

If x is an integer and |1-x|<2 then which of the following must be true?

|1-x| is just the distance between 1 and x on the number line. We are told that this distance is less than 2: --(-1)----1----3-- so, -1<x<3. Since given that x is an integer then x can be 0, 1 or 2.

A. x is not a prime number. Not true if x=2.
B. x^2+x is not a prime number. Not true if x=1.
C. x is positive. Not true if x=0.
D. Number of distinct positive factors of x+2 is a prime number. True for all three values of x.
E. x is not a multiple of an odd prime number. Not true if x=0, since zero is a multiple of every integer.

Answer: D.

Responding to pm.

D. Number of distinct positive factors of x+2 is a prime number. x+2 is 2, 3, or 4.

2 has 2 factors 1 and 2.
3 has 2 factors 1 and 3.
4 has 3 factors 1, 2 and 4.

The number of factors of each number is a prime number.

Hope it's clear.
avatar
demandi
Joined: 11 Feb 2014
Last visit: 22 May 2014
Posts: 1
Given Kudos: 8
Posts: 1
Kudos: 0
Kudos
Add Kudos
Bookmarks
Bookmark this Post
Bunuel,

Why does 2 have 2 factors? I thought the smallest factor of any number was 2.. Is there a definition difference that I am missing?

Thanks for the reply!
User avatar
Bunuel
User avatar
Math Expert
Joined: 02 Sep 2009
Last visit: 19 Nov 2025
Posts: 105,389
Own Kudos:
778,259
 [1]
Given Kudos: 99,977
Products:
Expert
Expert reply
Active GMAT Club Expert! Tag them with @ followed by their username for a faster response.
Posts: 105,389
Kudos: 778,259
 [1]
Kudos
Add Kudos
Bookmarks
Bookmark this Post
demandi
Bunuel,

Why does 2 have 2 factors? I thought the smallest factor of any number was 2.. Is there a definition difference that I am missing?

Thanks for the reply!

A factor is a positive integer which divides some integer without a remainder. Thus the smallest factor of any integer is 1.

The factors of 2 are 1 and 2.
avatar
dansa
Joined: 11 Dec 2013
Last visit: 18 Aug 2014
Posts: 4
Given Kudos: 1
Posts: 4
Kudos: 0
Kudos
Add Kudos
Bookmarks
Bookmark this Post
I think E ist also correct. as number 1 is not considered prime, as it has only one factor (itself).

Except if 0 is a multiple of every number!
User avatar
Bunuel
User avatar
Math Expert
Joined: 02 Sep 2009
Last visit: 19 Nov 2025
Posts: 105,389
Own Kudos:
778,259
 [4]
Given Kudos: 99,977
Products:
Expert
Expert reply
Active GMAT Club Expert! Tag them with @ followed by their username for a faster response.
Posts: 105,389
Kudos: 778,259
 [4]
3
Kudos
Add Kudos
1
Bookmarks
Bookmark this Post
dansa
E ist also correct1 The question is flawed!!

number 1 is not considered prime, as it has only one factor (itself).

Yes, 1 is NOT prime but it has nothing to do with option E.

E says: x is not a multiple of an odd prime number. IF x=0, then this option is not always true because 0 is a multiple of every integer, hence it's a multiple of all odd primes: 3, 5, 7, ....
avatar
farhanabad
Joined: 10 Mar 2013
Last visit: 05 Mar 2015
Posts: 9
Own Kudos:
1
 [1]
Given Kudos: 17
Posts: 9
Kudos: 1
 [1]
1
Kudos
Add Kudos
Bookmarks
Bookmark this Post
This might be a naive question and also highlights a gap in my understand but can you please explain how |1−x|<2 translates into "-2<(1-x)<2". Thank you.



SOURH7WK
sanjoo
If x is an integer and |1−x|<2 then which of the following must be true?

A) x is not a prime number
B) x^2+x is not a prime number
C) x is positive
D) Number of distinct positive factors of x+2 is a prime number
E) x is not a multiple of an odd prime number

|1−x|<2 = -2<(1-x)<2
= -3<-x<1
= 3>x>-1
So x can hold values of 0,1 & 2 to satisfy the condition. Now we can evaluate the choices.
A) 1 & 2 primes, so incorrect
B) 1^2+1=2 is a prime, so incorrect
C) 0 is not +ve, So incorrect
D) x+2= 2,3,or 4, here 2 has 2 factor(prime), 3 has 2 factor (prime) & 4 has 3factors (prime). Hence correct choice.
E) 2 is multiple of 1. So incorrect.

Hence Answer D.
User avatar
Bunuel
User avatar
Math Expert
Joined: 02 Sep 2009
Last visit: 19 Nov 2025
Posts: 105,389
Own Kudos:
778,259
 [4]
Given Kudos: 99,977
Products:
Expert
Expert reply
Active GMAT Club Expert! Tag them with @ followed by their username for a faster response.
Posts: 105,389
Kudos: 778,259
 [4]
2
Kudos
Add Kudos
2
Bookmarks
Bookmark this Post
farhanabad
This might be a naive question and also highlights a gap in my understand but can you please explain how |1−x|<2 translates into "-2<(1-x)<2". Thank you.



SOURH7WK
sanjoo
If x is an integer and |1−x|<2 then which of the following must be true?

A) x is not a prime number
B) x^2+x is not a prime number
C) x is positive
D) Number of distinct positive factors of x+2 is a prime number
E) x is not a multiple of an odd prime number

|1−x|<2 = -2<(1-x)<2
= -3<-x<1
= 3>x>-1
So x can hold values of 0,1 & 2 to satisfy the condition. Now we can evaluate the choices.
A) 1 & 2 primes, so incorrect
B) 1^2+1=2 is a prime, so incorrect
C) 0 is not +ve, So incorrect
D) x+2= 2,3,or 4, here 2 has 2 factor(prime), 3 has 2 factor (prime) & 4 has 3factors (prime). Hence correct choice.
E) 2 is multiple of 1. So incorrect.

Hence Answer D.

|1 − x| < 2:

(1 - x) < 2;
-(1 - x) < 2 --> -2 < 1 - x

Hence -2 < 1 - x < 2.

Theory on Abolute Values: math-absolute-value-modulus-86462.html

DS Abolute Values Questions to practice: search.php?search_id=tag&tag_id=37
PS Abolute Values Questions to practice: search.php?search_id=tag&tag_id=58

Hard set on Abolute Values: inequality-and-absolute-value-questions-from-my-collection-86939.html

Hope this helps.
avatar
farhanabad
Joined: 10 Mar 2013
Last visit: 05 Mar 2015
Posts: 9
Own Kudos:
Given Kudos: 17
Posts: 9
Kudos: 1
Kudos
Add Kudos
Bookmarks
Bookmark this Post
Bunuel - Thank you very much. It absolutely helps (no pun intended); and like I said there is a gap in my understanding since I believed that the absolute value of anything is always positive, hence I was viewing |x-1| as simply (x-1) and did not consider -(x-1). Thanks again.
User avatar
Bunuel
User avatar
Math Expert
Joined: 02 Sep 2009
Last visit: 19 Nov 2025
Posts: 105,389
Own Kudos:
778,259
 [1]
Given Kudos: 99,977
Products:
Expert
Expert reply
Active GMAT Club Expert! Tag them with @ followed by their username for a faster response.
Posts: 105,389
Kudos: 778,259
 [1]
1
Kudos
Add Kudos
Bookmarks
Bookmark this Post
farhanabad
Bunuel - Thank you very much. It absolutely helps (no pun intended); and like I said there is a gap in my understanding since I believed that the absolute value of anything is always positive, hence I was viewing |x-1| as simply (x-1) and did not consider -(x-1). Thanks again.

Absolute value of any number, expression, is more than or equal to zero but the expression in the modulus can be negative as well as positive. So, \(|x-1|\geq{0}\) but x-1 can be positive negative or 0.
avatar
rohitkumar1
Joined: 23 Nov 2014
Last visit: 11 Oct 2017
Posts: 48
Own Kudos:
Given Kudos: 64
Location: India
GMAT 1: 730 Q49 V40
GPA: 3.14
WE:Sales (Consumer Packaged Goods)
Kudos
Add Kudos
Bookmarks
Bookmark this Post
Bunuel
sanjoo
If x is an integer and |1−x|<2 then which of the following must be true?

A) x is not a prime number
B) x^2+x is not a prime number
C) x is positive
D) Number of distinct positive factors of x+2 is a prime number
E) x is not a multiple of an odd prime number

If x is an integer and |1-x|<2 then which of the following must be true?

|1-x| is just the distance between 1 and x on the number line. We are told that this distance is less than 2: --(-1)----1----3-- so, -1<x<3. Since given that x is an integer then x can be 0, 1 or 2.

A. x is not a prime number. Not true if x=2.
B. x^2+x is not a prime number. Not true if x=1.
C. x is positive. Not true if x=0.
D. Number of distinct positive factors of x+2 is a prime number. True for all three values of x.
E. x is not a multiple of an odd prime number. Not true if x=0, since zeo is a multiple of every integer.

Answer: D.


Hi again Bunuel,

Just one question. I know by trial and error that the below process is wrong. But why does the algebra not match the intuitive way of solving??? Could you pls point out where you think I am making an error? TIA.

Given |1-x| < 2

(a) If x>0: 1-x < 2 -> x > -1

But this is true only for x>=0 which is a more limiting condition than x > -1. So shouldn't the result of opening the modulus be x>=0?

(b) If x<0: -1+x < 2 -> x<3

But this is true only for x<0 which is a more limiting condition that x<3. So shouldn't the result of opening the modulus be x<0?

By the above logic x = 0. But I can clearly see that x = 1 and x =2 will also work - why the discrepancy :?:
User avatar
EgmatQuantExpert
User avatar
e-GMAT Representative
Joined: 04 Jan 2015
Last visit: 02 Apr 2024
Posts: 3,663
Own Kudos:
20,165
 [5]
Given Kudos: 165
Expert
Expert reply
Posts: 3,663
Kudos: 20,165
 [5]
5
Kudos
Add Kudos
Bookmarks
Bookmark this Post
avgroh
Bunuel
sanjoo
If x is an integer and |1−x|<2 then which of the following must be true?

A) x is not a prime number
B) x^2+x is not a prime number
C) x is positive
D) Number of distinct positive factors of x+2 is a prime number
E) x is not a multiple of an odd prime number

If x is an integer and |1-x|<2 then which of the following must be true?

|1-x| is just the distance between 1 and x on the number line. We are told that this distance is less than 2: --(-1)----1----3-- so, -1<x<3. Since given that x is an integer then x can be 0, 1 or 2.

A. x is not a prime number. Not true if x=2.
B. x^2+x is not a prime number. Not true if x=1.
C. x is positive. Not true if x=0.
D. Number of distinct positive factors of x+2 is a prime number. True for all three values of x.
E. x is not a multiple of an odd prime number. Not true if x=0, since zeo is a multiple of every integer.

Answer: D.


Hi again Bunuel,

Just one question. I know by trial and error that the below process is wrong. But why does the algebra not match the intuitive way of solving??? Could you pls point out where you think I am making an error? TIA.

Given |1-x| < 2

(a) If x>0: 1-x < 2 -> x > -1

But this is true only for x>=0 which is a more limiting condition than x > -1. So shouldn't the result of opening the modulus be x>=0?

(b) If x<0: -1+x < 2 -> x<3

But this is true only for x<0 which is a more limiting condition that x<3. So shouldn't the result of opening the modulus be x<0?

By the above logic x = 0. But I can clearly see that x = 1 and x =2 will also work - why the discrepancy :?:

Hi avgroh,

You are not getting the right result because you are considering the zero points of x when deciding the sign of the expression when it comes out of the modulus. We consider the zero points of the expression inside the modulus to decide the sign of the expression when it comes out of the modulus i.e. in this case zero points of (1-x). So we can solve this modulus as

1. When 1- x > 0
1 - x < 2 i.e. x > -1

2. When 1 - x < 0
-(1-x) < 2 i.e. x < 3

Combining the above we get the range as -1 < x < 3. Since x is an integer it can take values of only 0,1 and 2.

Just to add on to the concept, we write |x| = x if x > 0 and -x if x < 0. On the same line, we would write |x -1| = x-1 if x-1 > 0 and -(x-1) if x-1 < 0

Hope it helps :)

Regards
Harsh
User avatar
Nasahtahir
Joined: 30 Sep 2016
Last visit: 01 Feb 2025
Posts: 8
Given Kudos: 1
Posts: 8
Kudos: 0
Kudos
Add Kudos
Bookmarks
Bookmark this Post
Hi,

Would you mind having a look? This is what I did.

I 1-x I<2
-2<1-x<2
Subtracted -1 ie -3<-x<1
Multiplied by - 3>x>-1 Now I understand option D, zero is an integer correct? It is just not a positive integer?

Can you explain option D three distinct positive values ie in my case 2,1,0? Just a little confused or do I have it all wrong?
User avatar
Bunuel
User avatar
Math Expert
Joined: 02 Sep 2009
Last visit: 19 Nov 2025
Posts: 105,389
Own Kudos:
Given Kudos: 99,977
Products:
Expert
Expert reply
Active GMAT Club Expert! Tag them with @ followed by their username for a faster response.
Posts: 105,389
Kudos: 778,259
Kudos
Add Kudos
Bookmarks
Bookmark this Post
Nasahtahir
Hi,

Would you mind having a look? This is what I did.

I 1-x I<2
-2<1-x<2
Subtracted -1 ie -3<-x<1
Multiplied by - 3>x>-1 Now I understand option D, zero is an integer correct? It is just not a positive integer?

Can you explain option D three distinct positive values ie in my case 2,1,0? Just a little confused or do I have it all wrong?

|1-x|<2 means -1<x<3. Since given that x is an integer then x can be 0, 1 or 2.

D says: Number of distinct positive factors of x+2 is a prime number. x+2 is 2, 3, or 4.

2 has 2 factors 1 and 2.
3 has 2 factors 1 and 3.
4 has 3 factors 1, 2 and 4.

The number of factors of each number is a prime number.

Hope it's clear.
User avatar
BrentGMATPrepNow
User avatar
Major Poster
Joined: 12 Sep 2015
Last visit: 31 Oct 2025
Posts: 6,739
Own Kudos:
35,342
 [1]
Given Kudos: 799
Location: Canada
Expert
Expert reply
Posts: 6,739
Kudos: 35,342
 [1]
Kudos
Add Kudos
1
Bookmarks
Bookmark this Post
sanjoo
If x is an integer and |1 − x| < 2 then which of the following must be true?

(A) x is not a prime number
(B) x^2 + x is not a prime number
(C) x is positive
(D) Number of distinct positive factors of x + 2 is a prime number
(E) x is not a multiple of an odd prime number

Two properties involving absolute value inequalities:
Property #1: If |something| < k, then –k < something < k
Property #2: If |something| > k, then EITHER something > k OR something < -k

Note: these rules assume that k is positive

Since the given inequality, |1 − x| < 2, is in the form |something| < k, we know we need to apply Property #1

When we apply Property #1, we get: -2 < 1 - x < 2
Subtract 1 from all sides to get: -3 < -x < 1
Multiply all sides by -1 to get: 3 > x > -1 [ since we multiplied all sides of the inequality by a negative value, we reversed the direction of the inequality symbols]

If x is an INTEGER and if 3 > x > -1, then there are only three possible values of x: 0, 1 or 2

Now let's examine the five answer choices:
(A) x is not a prime number
Since x COULD equal 2, x COULD be prime.

(B) x^2 + x is not a prime number
If x = 1, then x^2 + x = 1^2 + 1 = 2, and 2 IS prime.

(C) x is positive
If x = 0, then x is NOT positive.

(D) Number of distinct positive factors of x + 2 is a prime number
If x = 0, then x + 2 = 2. 2 has TWO positive factors (1 and 2), and TWO IS a prime number.
If x = 1, then x + 2 = 3. 3 has TWO positive factors (1 and 3), and TWO IS a prime number.
If x = 2, then x + 2 = 4. 4 has THREE positive factors (1, 2 and 4), and THREE IS a prime number.

(E) x is not a multiple of an odd prime number
If x = 0, then x IS a multiple of an odd prime number

Answer: D
User avatar
anirchat
Joined: 30 Jun 2024
Last visit: 14 Nov 2025
Posts: 291
Own Kudos:
Given Kudos: 323
Posts: 291
Kudos: 44
Kudos
Add Kudos
Bookmarks
Bookmark this Post
E is also a probable option as I am not sure if I should consider 0 as a multiple of any number.
P.S. 1 is neither prime not compsite.
User avatar
Bunuel
User avatar
Math Expert
Joined: 02 Sep 2009
Last visit: 19 Nov 2025
Posts: 105,389
Own Kudos:
Given Kudos: 99,977
Products:
Expert
Expert reply
Active GMAT Club Expert! Tag them with @ followed by their username for a faster response.
Posts: 105,389
Kudos: 778,259
Kudos
Add Kudos
Bookmarks
Bookmark this Post
anirchat
E is also a probable option as I am not sure if I should consider 0 as a multiple of any number.
P.S. 1 is neither prime not compsite.

No, x can be 0, and 0 is a multiple of every number, including odd primes.

By the way, this doubt has already been addressed in this thread.
Moderators:
Math Expert
105389 posts
Tuck School Moderator
805 posts