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

 It is currently 18 Jan 2019, 20:18

### 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

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

## Events & Promotions

###### Events & Promotions in January
PrevNext
SuMoTuWeThFrSa
303112345
6789101112
13141516171819
20212223242526
272829303112
Open Detailed Calendar
• ### Free GMAT Strategy Webinar

January 19, 2019

January 19, 2019

07:00 AM PST

09:00 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.
• ### FREE Quant Workshop by e-GMAT!

January 20, 2019

January 20, 2019

07:00 AM PST

07:00 AM PST

Get personalized insights on how to achieve your Target Quant Score.

# A set is such that if m is in the set, (m + 3) is also in the set. If

Author Message
TAGS:

### Hide Tags

Math Expert
Joined: 02 Sep 2009
Posts: 52285
A set is such that if m is in the set, (m + 3) is also in the set. If  [#permalink]

### Show Tags

19 Sep 2018, 23:02
00:00

Difficulty:

35% (medium)

Question Stats:

48% (00:38) correct 52% (00:40) wrong based on 29 sessions

### HideShow timer Statistics

A set is such that if m is in the set, (m + 3) is also in the set. If −3 is in the set, which of the following is also in the set?

I. −6
II. 0
III. 6

(A) Only I
(B) Only II
(C) Only I and II
(D) Only II and III
(E) I, II and III

_________________
examPAL Representative
Joined: 07 Dec 2017
Posts: 868
A set is such that if m is in the set, (m + 3) is also in the set. If  [#permalink]

### Show Tags

Updated on: 20 Sep 2018, 13:11
Bunuel wrote:
A set is such that if m is in the set, (m + 3) is also in the set. If −3 is in the set, which of the following is also in the set?

I. −6
II. 0
III. 6

(A) Only I
(B) Only II
(C) Only I and II
(D) Only II and III
(E) I, II and III

As we are explicitly given a rule to follow, we'll follow it.
This is a Precise approach

If -3 is in the set, (-3)+3 = 0 is in the set. So II is true.
Since 0 is in the set, 0+3 = 3 is in the set and since 3 is in the set, 3 +3 = 6 is in the set.
So III is also true. We do not have information about numbers smaller than -3 and cannot conclude if I is true or not.

Note that a different, Logical approach would have been to recognize that what we are doing is creating a set out of an arithmetic sequence with a difference of 3. Since one of the elements is -3, a multiple of 3, then the set contains all multiples of 3 starting from some number. The first number has to be at least -3 so II and III are true but we do not know if the first number in the set is smaller/equal to -6 or not so cannot conclude if I is true.
_________________

Originally posted by DavidTutorexamPAL on 19 Sep 2018, 23:10.
Last edited by DavidTutorexamPAL on 20 Sep 2018, 13:11, edited 1 time in total.
CEO
Status: GMATINSIGHT Tutor
Joined: 08 Jul 2010
Posts: 2726
Location: India
GMAT: INSIGHT
Schools: Darden '21
WE: Education (Education)
A set is such that if m is in the set, (m + 3) is also in the set. If  [#permalink]

### Show Tags

20 Sep 2018, 02:58
Bunuel wrote:
A set is such that if m is in the set, (m + 3) is also in the set. If −3 is in the set, which of the following is also in the set?

I. −6
II. 0
III. 6

(A) Only I
(B) Only II
(C) Only I and II
(D) Only II and III
(E) I, II and III

NOTE: This is forward progressing series i.e. if m is in set (m+3) also will be in the set but please NOTE that if m is in the set (m-3) will not essentially be in set which is what is misunderstood by many test takers

i.e. if -3 is in set then {0,3,6,9,12,15....} will also be in the set hence

II and III will always be in the set

_________________

Prosper!!!
GMATinsight
Bhoopendra Singh and Dr.Sushma Jha
e-mail: info@GMATinsight.com I Call us : +91-9999687183 / 9891333772
Online One-on-One Skype based classes and Classroom Coaching in South and West Delhi
http://www.GMATinsight.com/testimonials.html

ACCESS FREE GMAT TESTS HERE:22 ONLINE FREE (FULL LENGTH) GMAT CAT (PRACTICE TESTS) LINK COLLECTION

A set is such that if m is in the set, (m + 3) is also in the set. If &nbs [#permalink] 20 Sep 2018, 02:58
Display posts from previous: Sort by