NEW HERE? LEARN MORE
closeclose
It is currently 19 Apr 2024, 14:49
Register
GMAT Focus Tests
Decision Tracker
My Rewards
New posts
New comers' posts

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

If j is an integer, is k an integer?

6 posts Go to First Unread Post
Print view
NEW TOPIC
POST REPLY
Question banks

GMAT Question Banks

Downloads
My Bookmarks
Reviews
SORT BY:
Date
Kudos
User avatar
L
Bunuel
Math Expert
Joined: 02 Sep 2009
Posts: 92760
CAT Tests Forum Quiz Mode
If j is an integer, is k an integer? [#permalink] New post  27 Dec 2016, 08:59
Expert Reply
00:00
A
B
C
D
E

Difficulty:

55% (hard)

Question Stats:

54% (01:27) correct 46% (01:17) wrong based on 127 sessions
Hide Show timer Statistics
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
Official Answer and Stats are available only to registered users. Register/Login.

_________________
New to the GMAT CLUB Forum?

My Signature Questions' Collection:


What are GMAT Club Tests?
Extra-hard Quant Tests with Brilliant Analytics
Signature Read More
request expert reply
User avatar
L
rohit8865
Director
Director
Joined: 05 Mar 2015
Posts: 852
Reviews Badge
Re: If j is an integer, is k an integer? [#permalink] New post  27 Dec 2016, 10:12
Bunuel wrote:
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
User avatar
G
Madhavi1990
Senior Manager
Senior Manager
Joined: 15 Jan 2017
Posts: 259
Re: If j is an integer, is k an integer? [#permalink] New post  15 Nov 2017, 15:30
rohit8865 wrote:
Bunuel wrote:
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 :)
avatar
S
jxav
Current Student
Joined: 09 Mar 2017
Posts: 85
Location: Netherlands
Concentration: General Management, Finance
GMAT 1: 690 Q45 V40
GRE 1: Q168 V156
Re: If j is an integer, is k an integer? [#permalink] New post  15 Nov 2017, 18:36
1
Kudos
Madhavi1990 wrote:
rohit8865 wrote:
Bunuel wrote:
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 :)

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
S
Manick9
Manager
Manager
Joined: 25 May 2016
Posts: 79
Location: Singapore
Concentration: Finance, General Management
GMAT 1: 620 Q46 V30
Re: If j is an integer, is k an integer? [#permalink] New post  11 Dec 2018, 07:46
1
Kudos
(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
P
fitzpratik
Manager
Manager
Joined: 17 Oct 2016
Posts: 227
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 (Health Care)
Reviews Badge
If j is an integer, is k an integer? [#permalink] New post  11 Dec 2018, 08:01
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
_________________
_____________________
Chasing the dragon
Signature Read More
GMAT Club Bot
gmatclubot
If j is an integer, is k an integer? [#permalink]
11 Dec 2018, 08:01
NEW TOPIC
POST REPLY
Downloads
My Bookmarks
Reviews
Moderator:
Bunuel
Math Expert
92760 posts

cron

Powered by phpBB © phpBB Group | Emoji artwork provided by EmojiOne
Main navigation
GMAT Resources
Partners
MBA Resources
www.gmac.com|www.mba.com | | GMAT Club Rules | Terms and Conditions