Last visit was: 25 Apr 2026, 13:15 It is currently 25 Apr 2026, 13:15
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
555-605 (Medium)|   Functions and Custom Characters|                  
User avatar
Bunuel
User avatar
Math Expert
Joined: 02 Sep 2009
Last visit: 25 Apr 2026
Posts: 109,832
Own Kudos:
811,259
 [55]
Given Kudos: 105,886
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: 109,832
Kudos: 811,259
 [55]
The symbol represents which one of the following operations: additio 02 Aug 2018, 23:49
1
Kudos
Add Kudos
54
Bookmarks
Bookmark this Post
00:00
Start Timer
Pause Timer
Resume Timer
Show Answer
Hide
Show
History
D
Be sure to select an answer first to save it in the Error Log before revealing the correct answer (OA)!

Difficulty:

25% (medium)

Question Stats:

73% (01:33) correct 27% (01:58) wrong based on 2226 sessions

History

Date
Time
Result
Not Attempted Yet
The symbol Δ represents which one of the following operations: addition, subtraction, or multiplication?


(1) aΔ(bΔc) ≠ aΔ(cΔb) for some numbers a, b, and c.
(2) aΔ(bΔc) ≠ (aΔb)Δc for some numbers a, b, and c.


(DS08352)
ShowHide Answer
Official Answer
D
Need more similar questions? Run a 5 to 10 question quiz in GMAT Club Forum Quiz →
Most Helpful Reply
User avatar
PKN
User avatar
Joined: 01 Oct 2017
Last visit: 11 Oct 2025
Posts: 809
Own Kudos:
1,637
 [6]
Given Kudos: 41
Status:Learning stage
WE:Supply Chain Management (Energy)
Posts: 809
Kudos: 1,637
 [6]
The symbol represents which one of the following operations: additio 03 Aug 2018, 02:35
3
Kudos
Add Kudos
3
Bookmarks
Bookmark this Post
Bunuel
The symbol Δ represents which one of the following operations: addition, subtraction, or multiplication?


(1) aΔ(bΔc) ≠ aΔ(cΔb) for some numbers a, b, and c.
(2) aΔ(bΔc) ≠ (aΔb)Δc for some numbers a, b, and c.


NEW question from GMAT® Quantitative Review 2019


(DS08352)
Show more

Question stem:-Type operation is to be unique.

St1:- aΔ(bΔc) ≠ aΔ(cΔb) for some numbers a, b, and c.
Only subtraction satisfy this condition.
Hence, sufficient.

St2:-Δ(bΔc) ≠ (aΔb)Δc for some numbers a, b, and c.
Only subtraction satisfy this condition.
Hence, sufficient.

Ans. (D)
General Discussion
User avatar
sudarshan22
User avatar
Retired Moderator
Joined: 30 Jan 2015
Last visit: 10 Nov 2019
Posts: 628
Own Kudos:
2,477
 [3]
Given Kudos: 1,131
Location: India
Concentration: Operations, Marketing
GPA: 3.5
Posts: 628
Kudos: 2,477
 [3]
The symbol represents which one of the following operations: additio 03 Aug 2018, 03:34
1
Kudos
Add Kudos
2
Bookmarks
Bookmark this Post
(1) aΔ(bΔc) ≠ aΔ(cΔb) for some numbers a, b, and c.
Addition, and multiplication would always be equal from same numbers, so it has to be subtraction
Sufficient

(2) aΔ(bΔc) ≠ (aΔb)Δc for some numbers a, b, and c.
Addition, and multiplication would always be equal from same numbers, so it has to be subtraction
Sufficient

Hence, D.
User avatar
Salsanousi
User avatar
Joined: 19 Oct 2013
Last visit: 29 Dec 2020
Posts: 391
Own Kudos:
358
Given Kudos: 117
Location: Kuwait
GPA: 3.2
WE:Engineering (Real Estate)
Posts: 391
Kudos: 358
The symbol represents which one of the following operations: additio 18 Oct 2018, 08:47
Kudos
Add Kudos
Bookmarks
Bookmark this Post
Bunuel
The symbol Δ represents which one of the following operations: addition, subtraction, or multiplication?


(1) aΔ(bΔc) ≠ aΔ(cΔb) for some numbers a, b, and c.
(2) aΔ(bΔc) ≠ (aΔb)Δc for some numbers a, b, and c.


NEW question from GMAT® Quantitative Review 2019


(DS08352)
Show more

Let a = 3, b = 2, c = 1

3 - (2-1) = 3 - 1 = 2

3 - (1 - 2) = 3 - (-1) = 4 only subtraction satisfies this.

Same concept can be applied to statement 2)

Answer choice D
User avatar
EatMyDosa
User avatar
Joined: 06 Jan 2017
Last visit: 01 Dec 2022
Posts: 81
Own Kudos:
114
Given Kudos: 283
Location: India
Concentration: General Management, Finance
GPA: 3.33
Products:
My Reviews
Posts: 81
Kudos: 114
The symbol represents which one of the following operations: additio 11 Sep 2020, 23:41
Kudos
Add Kudos
Bookmarks
Bookmark this Post
In such questions, it is much easier to solve if you assign some numbers to variables a, b, and c.
User avatar
MHIKER
User avatar
Joined: 14 Jul 2010
Last visit: 24 May 2021
Posts: 939
Own Kudos:
5,817
Given Kudos: 690
Status:No dream is too large, no dreamer is too small
Concentration: Accounting
Posts: 939
Kudos: 5,817
The symbol represents which one of the following operations: additio 16 Dec 2020, 07:47
Kudos
Add Kudos
Bookmarks
Bookmark this Post
Bunuel
The symbol Δ represents which one of the following operations: addition, subtraction, or multiplication?


(1) aΔ(bΔc) ≠ aΔ(cΔb) for some numbers a, b, and c.
(2) aΔ(bΔc) ≠ (aΔb)Δc for some numbers a, b, and c.
Show more

Addition and multiplication are always equal for the same numbers. But subtraction matters for parenthesis and order of numbers.

The answer of this question is \(D\)
User avatar
kris19
User avatar
Joined: 24 Sep 2014
Last visit: 19 Feb 2023
Posts: 70
Own Kudos:
125
Given Kudos: 261
Concentration: General Management, Technology
Posts: 70
Kudos: 125
The symbol represents which one of the following operations: additio 16 Dec 2020, 20:20
Kudos
Add Kudos
Bookmarks
Bookmark this Post
MHIKER
Bunuel
The symbol Δ represents which one of the following operations: addition, subtraction, or multiplication?


(1) aΔ(bΔc) ≠ aΔ(cΔb) for some numbers a, b, and c.
(2) aΔ(bΔc) ≠ (aΔb)Δc for some numbers a, b, and c.

Addition and multiplication are always equal for the same numbers. But subtraction matters for parenthesis and order of numbers.

The answer of this question is \(D\)
Show more

if we assume b, c as 0, then subtraction is also valid..!
User avatar
MHIKER
User avatar
Joined: 14 Jul 2010
Last visit: 24 May 2021
Posts: 939
Own Kudos:
5,817
 [1]
Given Kudos: 690
Status:No dream is too large, no dreamer is too small
Concentration: Accounting
Posts: 939
Kudos: 5,817
 [1]
The symbol represents which one of the following operations: additio 17 Dec 2020, 01:37
1
Kudos
Add Kudos
Bookmarks
Bookmark this Post
kris19
MHIKER
Bunuel
The symbol Δ represents which one of the following operations: addition, subtraction, or multiplication?


(1) aΔ(bΔc) ≠ aΔ(cΔb) for some numbers a, b, and c.
(2) aΔ(bΔc) ≠ (aΔb)Δc for some numbers a, b, and c.

Addition and multiplication are always equal for the same numbers. But subtraction matters for parenthesis and order of numbers.

The answer of this question is \(D\)

if we assume b, c as 0, then subtraction is also valid..!
Show more

If you take b=c=0
Then
(1)aΔ(0-0)=aΔ(0Δ0) or a=a both sides are equal. Contradictory with the statements.

(2) Same as option 1.

But I'm confused with me. I think we take any digit for a,b & c including ZERO. Bunuel help needed.
User avatar
CEdward
User avatar
Joined: 11 Aug 2020
Last visit: 14 Apr 2022
Posts: 1,161
Own Kudos:
289
 [1]
Given Kudos: 332
Posts: 1,161
Kudos: 289
 [1]
The symbol represents which one of the following operations: additio 09 Apr 2021, 14:17
1
Kudos
Add Kudos
Bookmarks
Bookmark this Post
Oh wow, I must be seeing stars. I considered division as an operation.

Answer is D though.

Only subtration works.
avatar
RR1996
avatar
Joined: 08 Apr 2021
Last visit: 31 May 2021
Posts: 2
Given Kudos: 186
Posts: 2
Kudos: 0
The symbol represents which one of the following operations: additio 09 Apr 2021, 20:41
Kudos
Add Kudos
Bookmarks
Bookmark this Post
I think the answer should be B.

This is because lets take two options for values of a,b,c - 1,2,2 & 5,4,2 respectively

Then, when we take 1,2,2 in statement A, LHS = RHS
But, when we take 5,4,2 as values in statement A, LHS does not equal RHS therefore, statement A is not suff

Whereas, in statement B, both these values result in the same answer when subtracting
avatar
Varane
avatar
Joined: 24 Mar 2022
Last visit: 16 Dec 2022
Posts: 64
Own Kudos:
6
Given Kudos: 470
Posts: 64
Kudos: 6
The symbol represents which one of the following operations: additio 14 May 2022, 04:49
Kudos
Add Kudos
Bookmarks
Bookmark this Post
It's not mentioned anywhere that a,b and c need to be unique.
So statement 1 on Division if b=c.
And also on subtraction if b and c are both equal.

Confusing.

Posted from my mobile device
User avatar
bumpbot
User avatar
Non-Human User
Joined: 09 Sep 2013
Last visit: 04 Jan 2021
Posts: 38,985
Own Kudos:
1,118
Posts: 38,985
Kudos: 1,118
The symbol represents which one of the following operations: additio 16 May 2023, 07:17
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
109831 posts
kingbucky
498 posts
Gmat860sanskar
212 posts