Last visit was: 24 Apr 2026, 04:07 It is currently 24 Apr 2026, 04:07
Home
Messages
Tests
Schools
Events
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.
Go to My Error Log Learn more
Close
Request Expert Reply
Confirm Cancel
Back to Forum
Create Topic
User avatar
Bunuel
User avatar
Math Expert
Joined: 02 Sep 2009
Last visit: 24 Apr 2026
Posts: 109,809
Own Kudos:
810,934
 [4]
Given Kudos: 105,869
Products:
GMAT Club Tests Forum Quiz
Expert
Expert reply
Active GMAT Club Expert! Tag them with @ followed by their username for a faster response.
Posts: 109,809
Kudos: 810,934
 [4]
If j is an integer, is k an integer? 27 Dec 2016, 08:59
Kudos
Add Kudos
4
Bookmarks
Bookmark this Post
00:00
Start Timer
Pause Timer
Resume Timer
Show Answer
Hide
Show
History
C
Be sure to select an answer first to save it in the Error Log before revealing the correct answer (OA)!

Difficulty:

55% (hard)

Question Stats:

58% (01:30) correct 42% (01:12) wrong based on 180 sessions

History

Date
Time
Result
Not Attempted Yet
If j is an integer, is k an integer?

(1) j – 2k is an integer.
(2) 5k – j is an integer.
ShowHide Answer
Official Answer
C
User avatar
rohit8865
User avatar
Joined: 05 Mar 2015
Last visit: 19 Apr 2026
Posts: 815
Own Kudos:
1,008
Given Kudos: 45
Products:
My Reviews
Posts: 815
Kudos: 1,008
If j is an integer, is k an integer? 27 Dec 2016, 10:12
Kudos
Add Kudos
Bookmarks
Bookmark this Post
Bunuel
If j is an integer, is k an integer?

(1) j – 2k is an integer.
(2) 5k – j is an integer.
Show more


let j=10
(1) then, if k=1 then yes
k=1/2 No ....insuff

(2) k=1 then yes
k=1/5 then No...insuff..

combined k must be ineteger....suff

Ans C
User avatar
Madhavi1990
User avatar
Joined: 15 Jan 2017
Last visit: 15 Jul 2021
Posts: 250
Own Kudos:
93
Given Kudos: 931
Posts: 250
Kudos: 93
If j is an integer, is k an integer? 15 Nov 2017, 15:30
Kudos
Add Kudos
Bookmarks
Bookmark this Post
rohit8865
Bunuel
If j is an integer, is k an integer?

(1) j – 2k is an integer.
(2) 5k – j is an integer.


let j=10
(1) then, if k=1 then yes
k=1/2 No ....insuff

(2) k=1 then yes
k=1/5 then No...insuff..

combined k must be ineteger....suff


Ans C
Show more

Questions asks if k is an integer? J is already integer. (it can be positive or negative).

A) is quite clear, its is INSUFFICIENT

in B if, k = 0.2 (which is 1/5) --> 5(0.2) - j (the integer) --> 1 - 2 = -1 there fore k is NOT integer.(is j is 2, 3, 4.. since answer is an integer, so answer can be negative or positive).
On the other hand, if k =1 --> then 5 - 4 (if j = 4) --> 1 or 5 - (-2) --> 7. Again K is Integer.
So both are INSUFFICIENT.
Hence E

How is C the answer? Could you give me a little detail into the solving? Thank you, it would be highly appreciated :)
avatar
jxav
avatar
Current Student
Joined: 09 Mar 2017
Last visit: 18 Dec 2020
Posts: 79
Own Kudos:
52
 [1]
Given Kudos: 30
Location: Netherlands
Concentration: General Management, Finance
GMAT 1: 690 Q45 V40
GRE 1: Q168 V156
GMAT 1: 690 Q45 V40
GRE 1: Q168 V156
Posts: 79
Kudos: 52
 [1]
If j is an integer, is k an integer? 15 Nov 2017, 18:36
1
Kudos
Add Kudos
Bookmarks
Bookmark this Post
Madhavi1990
rohit8865
Bunuel
If j is an integer, is k an integer?

(1) j – 2k is an integer.
(2) 5k – j is an integer.


let j=10
(1) then, if k=1 then yes
k=1/2 No ....insuff

(2) k=1 then yes
k=1/5 then No...insuff..

combined k must be ineteger....suff


Ans C

Questions asks if k is an integer? J is already integer. (it can be positive or negative).

A) is quite clear, its is INSUFFICIENT

in B if, k = 0.2 (which is 1/5) --> 5(0.2) - j (the integer) --> 1 - 2 = -1 there fore k is NOT integer.(is j is 2, 3, 4.. since answer is an integer, so answer can be negative or positive).
On the other hand, if k =1 --> then 5 - 4 (if j = 4) --> 1 or 5 - (-2) --> 7. Again K is Integer.
So both are INSUFFICIENT.
Hence E

How is C the answer? Could you give me a little detail into the solving? Thank you, it would be highly appreciated :)
Show more
Hi,

There is no single non-integer which can be multiplied by either 2 or 5, and still results in an integer. So since the number results in an integer when multiplied by either 2 or 5, it must be an integer. Hope this helps!



Sent from my SM-G935F using GMAT Club Forum mobile app
avatar
Manick9
avatar
Joined: 25 May 2016
Last visit: 07 Jan 2025
Posts: 78
Own Kudos:
85
 [1]
Given Kudos: 497
Location: Singapore
Concentration: Finance, General Management
GMAT 1: 620 Q46 V30
GMAT 1: 620 Q46 V30
Posts: 78
Kudos: 85
 [1]
If j is an integer, is k an integer? 11 Dec 2018, 07:46
1
Kudos
Add Kudos
Bookmarks
Bookmark this Post
(1) j-2k
k could be 1 or 1/2
Insufficient information

(2) 5k-j
If k=1 then yes
k=1/2 then insufficient information

combine them and we know k times 2 or k times 5 is an integer and therefore sufficient.
Option C
User avatar
fitzpratik
User avatar
Joined: 17 Oct 2016
Last visit: 08 Mar 2021
Posts: 224
Own Kudos:
496
Given Kudos: 49
Location: India
Concentration: General Management, Healthcare
Schools: Owen '22 (I) Boston U '22 (A$) Jones '22 (WL) Kenan-Flagler '22 (WA) Olin '22 (WA$)
GPA: 3.05
WE:Pharmaceuticals (Healthcare/Pharmaceuticals)
Products:
My Reviews
Schools: Owen '22 (I) Boston U '22 (A$) Jones '22 (WL) Kenan-Flagler '22 (WA) Olin '22 (WA$)
Posts: 224
Kudos: 496
If j is an integer, is k an integer? 11 Dec 2018, 08:01
Kudos
Add Kudos
Bookmarks
Bookmark this Post
1 and 2 alone are clearly not sufficient

Now, If we combine 1 and 2:

2K is an integer, and 5K is integer
for 5K to be integer, k = 0.2, 0.4, 0.6, 0.8, 1.0, 1.2....and so on...
but 2K cannot be an integer if k = 0.2, 0.4, 0.6, 0.8, 1.0, 1.2.

So K has to be an integer if 2k and 5k are integer.

1 and 2 combined are sufficient to answer the question
User avatar
bumpbot
User avatar
Non-Human User
Joined: 09 Sep 2013
Last visit: 04 Jan 2021
Posts: 38,967
Own Kudos:
1,117
Posts: 38,967
Kudos: 1,117
If j is an integer, is k an integer? 03 Dec 2024, 01:39
Kudos
Add Kudos
Bookmarks
Bookmark this Post
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.
Moderators:
Bunuel
Math Expert
109809 posts
kingbucky
498 posts
Gmat860sanskar
212 posts