Summer is Coming! Join the Game of Timers Competition to Win Epic Prizes. Registration is Open. Game starts Mon July 1st.

It is currently 18 Jul 2019, 07:02

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

(3^−1 − 2^−1)^−1

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

Hide Tags

Find Similar Topics 
Math Expert
User avatar
V
Joined: 02 Sep 2009
Posts: 56251
(3^−1 − 2^−1)^−1  [#permalink]

Show Tags

New post 21 Aug 2018, 06:16
00:00
A
B
C
D
E

Difficulty:

  5% (low)

Question Stats:

83% (00:39) correct 17% (00:51) wrong based on 82 sessions

HideShow timer Statistics


CEO
CEO
User avatar
V
Joined: 12 Sep 2015
Posts: 3848
Location: Canada
Re: (3^−1 − 2^−1)^−1  [#permalink]

Show Tags

New post 21 Aug 2018, 06:26
Top Contributor
Bunuel wrote:
\((3^{−1} − 2^{−1})^{−1}\)

A. -6
B. -5
C. -1/6
D. 16
E. 6


\(3^{−1}\) = 1/3
\(2^{−1}\) = 1/2
And 1/3 - 1/2 = 2/6 - 3/6 = -1/6

So, \((3^{−1} − 2^{−1})^{−1}\) = (1/3 - 1/2)^(-1)
= (-1/6)^(-1)

Finally, there's a nice rule that says (a/b)^(-n) = (b/a)^n
So, (-1/6)^(-1) = (-6/1)^(1)
= -6/1
= -6

Answer: A

Cheers,
Brent
_________________
Test confidently with gmatprepnow.com
Image
Board of Directors
User avatar
P
Status: QA & VA Forum Moderator
Joined: 11 Jun 2011
Posts: 4512
Location: India
GPA: 3.5
WE: Business Development (Commercial Banking)
GMAT ToolKit User
Re: (3^−1 − 2^−1)^−1  [#permalink]

Show Tags

New post 21 Aug 2018, 11:19
Bunuel wrote:
\((3^{−1} − 2^{−1})^{−1}\)

A. -6
B. -5
C. -1/6
D. 16
E. 6

\((3^{−1} − 2^{−1})\)

\(= \frac{1}{3} - \frac{1}{2}\)

\(= \frac{2 - 3}{6}\)

\(-\frac{1}{6} = -6\)

Now, \(= (-\frac{1}{6})^{-1}\), Answer must be (A) \(-6\)
_________________
Thanks and Regards

Abhishek....

PLEASE FOLLOW THE RULES FOR POSTING IN QA AND VA FORUM AND USE SEARCH FUNCTION BEFORE POSTING NEW QUESTIONS

How to use Search Function in GMAT Club | Rules for Posting in QA forum | Writing Mathematical Formulas |Rules for Posting in VA forum | Request Expert's Reply ( VA Forum Only )
GMAT Club Bot
Re: (3^−1 − 2^−1)^−1   [#permalink] 21 Aug 2018, 11:19
Display posts from previous: Sort by

(3^−1 − 2^−1)^−1

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





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