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

It is currently 20 Oct 2019, 02:00

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

(1.0004)(0.9998) – (1.0002)(0.9996) =

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

Hide Tags

Find Similar Topics 
Director
Director
User avatar
V
Joined: 12 Feb 2015
Posts: 917
(1.0004)(0.9998) – (1.0002)(0.9996) =  [#permalink]

Show Tags

New post Updated on: 01 Jul 2018, 00:34
3
4
00:00
A
B
C
D
E

Difficulty:

  55% (hard)

Question Stats:

60% (02:08) correct 40% (01:55) wrong based on 111 sessions

HideShow timer Statistics

(1.0004)(0.9998) – (1.0002)(0.9996) =

(A) 0.00000002
(B) 0.00000004
(C) 0.00000008
(D) 0.0004
(E) 0.0002

_________________
________________
Manish :geek:

"Only I can change my life. No one can do it for me"

Originally posted by CAMANISHPARMAR on 16 Jun 2018, 09:55.
Last edited by CAMANISHPARMAR on 01 Jul 2018, 00:34, edited 1 time in total.
Most Helpful Community Reply
Director
Director
User avatar
V
Joined: 12 Feb 2015
Posts: 917
Re: (1.0004)(0.9998) – (1.0002)(0.9996) =  [#permalink]

Show Tags

New post Updated on: 01 Jul 2018, 00:33
5
Let x = 0.0002.

Therefore (1.0004)(0.9998) – (1.0002)(0.9996) can be written as:-

= (1 + 2x)(1 – x) – (1 + x)(1 – 2x) = 2x [On simplification]

Substitute x = 0.0002 in 2x

Therefore 2(0.0002) = 0.0004.

Correct Answer is Option (D)
_________________
________________
Manish :geek:

"Only I can change my life. No one can do it for me"

Originally posted by CAMANISHPARMAR on 16 Jun 2018, 10:02.
Last edited by CAMANISHPARMAR on 01 Jul 2018, 00:33, edited 1 time in total.
General Discussion
Senior PS Moderator
User avatar
V
Joined: 26 Feb 2016
Posts: 3335
Location: India
GPA: 3.12
Re: (1.0004)(0.9998) – (1.0002)(0.9996) =  [#permalink]

Show Tags

New post 16 Jun 2018, 11:56
1
CAMANISHPARMAR wrote:
(1.0004)(0.9998) – (1.0002)(0.9996) =

A. 0.00000002
B. 0.00000004
C. 0.00000008
D. 0.0004
E. 0.0002


(1.0004)(0.9998) is of form \((a + b)(a - b) = (a^2 - b^2)\) where a = 1.0001 and b = 0.0003
(1.0002)(0.9996) is of form \((a + b)(a - b) = (a^2 - b^2)\) where a = 0.9999 and b = 0.0003

\((1.0004)(0.9998) – (1.0002)(0.9996) = (1.0001)^2-(0.0003)^2-(0.9999)^2+(0.0003)^2 = (1.0001)^2 - (0.9999)^2 = 2(0.0002)\)

Therefore, the value of the expression is 0.0004(Option D)
_________________
You've got what it takes, but it will take everything you've got
Manager
Manager
avatar
S
Joined: 18 Jul 2017
Posts: 57
CAT Tests
Re: (1.0004)(0.9998) – (1.0002)(0.9996) =  [#permalink]

Show Tags

New post 19 Jun 2018, 17:24
pushpitkc

I didn't understand how did you get this?

(1.0001)2−(0.9999)2=2(0.0002)
Math Expert
avatar
V
Joined: 02 Aug 2009
Posts: 7988
Re: (1.0004)(0.9998) – (1.0002)(0.9996) =  [#permalink]

Show Tags

New post 19 Jun 2018, 19:58
wishalsp333 wrote:
pushpitkc

I didn't understand how did you get this?

(1.0001)2−(0.9999)2=2(0.0002)


Hi...
\((1.0004)(0.9998)-(1.0002)(0.9996)=(1.0001+0.0003)(1.0001-0.0003)-(0.9999+0.0003)(0.9999-0.0003)=\)

\((1.0001^2-0.0003^2)-(0.9999^2-0.0003^2)...\)

\(=> 1.0001^2-0.0003^2-0.9999^2+0.0003^2=1.0001^2-0.9999^2=(1.0001-0.9999)(1.0001+0.9999)=0.0002*2=0.0004\)
_________________
GMAT Club Bot
Re: (1.0004)(0.9998) – (1.0002)(0.9996) =   [#permalink] 19 Jun 2018, 19:58
Display posts from previous: Sort by

(1.0004)(0.9998) – (1.0002)(0.9996) =

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





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