It is currently 21 Feb 2018, 15:15

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

Events & Promotions

Events & Promotions in June
Open Detailed Calendar

The symbol ⊙ represents one of the operations: addition, subtraction,

  new topic post reply Question banks Downloads My Bookmarks Reviews Important topics  
Author Message
TAGS:

Hide Tags

Expert Post
Math Revolution GMAT Instructor
User avatar
D
Joined: 16 Aug 2015
Posts: 4897
GPA: 3.82
The symbol ⊙ represents one of the operations: addition, subtraction, [#permalink]

Show Tags

New post 09 Jan 2018, 02:52
00:00
A
B
C
D
E

Difficulty:

  15% (low)

Question Stats:

84% (00:31) correct 16% (00:23) wrong based on 43 sessions

HideShow timer Statistics

[GMAT math practice question]

The symbol ⊙ represents one of the operations: addition, subtraction, multiplication, and division. Is 2⊙2=4?

1) 1⊙1=1
2) (-1) ⊙ (-1)=0
[Reveal] Spoiler: OA

_________________

MathRevolution: Finish GMAT Quant Section with 10 minutes to spare
The one-and-only World’s First Variable Approach for DS and IVY Approach for PS with ease, speed and accuracy.
Find a 10% off coupon code for GMAT Club members.
“Receive 5 Math Questions & Solutions Daily”
Unlimited Access to over 120 free video lessons - try it yourself
See our Youtube demo

Expert Post
examPAL Representative
User avatar
B
Joined: 07 Dec 2017
Posts: 165
Re: The symbol ⊙ represents one of the operations: addition, subtraction, [#permalink]

Show Tags

New post 09 Jan 2018, 03:33
MathRevolution wrote:
[GMAT math practice question]

The symbol ⊙ represents one of the operations: addition, subtraction, multiplication, and division. Is 2⊙2=4?

1) 1⊙1=1
2) (-1) ⊙ (-1)=0


As we have only 4 options, we'll just list them all.
This is an Alternative approach.

(1) Since
1*1 = 1
1/1 =1
1 + 1 = 2
1-1 =0
then ⊙ can be * or / and 2⊙2 is 4 or 1.
Insufficient!

(2) Since
-1 * -1 = 1
-1 / -1 =1
-1 + -1 = -2
-1 - -1 =0
Then ⊙ must be - and 2⊙2=0
Sufficient to answer NO.

(B) is our answer.
_________________

David
Senior tutor at examPAL
Signup for a free GMAT course
Image
Image

Expert Post
Math Revolution GMAT Instructor
User avatar
D
Joined: 16 Aug 2015
Posts: 4897
GPA: 3.82
Re: The symbol ⊙ represents one of the operations: addition, subtraction, [#permalink]

Show Tags

New post 11 Jan 2018, 00:39
=>

Forget conventional ways of solving math questions. For DS problems, the VA (Variable Approach) method is the quickest and easiest way to find the answer without actually solving the problem. Remember that equal numbers of variables and independent equations ensure a solution.
The first step of the VA (Variable Approach) method is to modify the original condition and the question, and then recheck the question.
Since only 2 + 2 = 4 and 2 * 2 = 4, the question asks if ⊙ is addition or multiplication.
Condition 1)
Since 1 * 1 = 1 and 1 / 1 = 1, ⊙ is multiplication or division.
Condition 1) is not sufficient.
Condition 2)
Since (-1) – (-1) = 0, ⊙ is subtraction. The answer is “no”.
CMT1 states that “no” is also an answer.
Condition 2) is sufficient.

Therefore, the answer is B.
Answer: B
_________________

MathRevolution: Finish GMAT Quant Section with 10 minutes to spare
The one-and-only World’s First Variable Approach for DS and IVY Approach for PS with ease, speed and accuracy.
Find a 10% off coupon code for GMAT Club members.
“Receive 5 Math Questions & Solutions Daily”
Unlimited Access to over 120 free video lessons - try it yourself
See our Youtube demo

Intern
Intern
avatar
Joined: 04 Jan 2018
Posts: 6
Re: The symbol ⊙ represents one of the operations: addition, subtraction, [#permalink]

Show Tags

New post 11 Jan 2018, 01:12
New to this topic and really thanks for sharing this useful ideas.
_________________

essay writing service UK

Re: The symbol ⊙ represents one of the operations: addition, subtraction,   [#permalink] 11 Jan 2018, 01:12
Display posts from previous: Sort by

The symbol ⊙ represents one of the operations: addition, subtraction,

  new topic post reply Question banks Downloads My Bookmarks Reviews Important topics  


GMAT Club MBA Forum Home| About| Terms and Conditions| GMAT Club Rules| Contact| Sitemap

Powered by phpBB © phpBB Group | Emoji artwork provided by EmojiOne

Kindly note that the GMAT® test is a registered trademark of the Graduate Management Admission Council®, and this site has neither been reviewed nor endorsed by GMAC®.