Find all School-related info fast with the new School-Specific MBA Forum

It is currently 22 Sep 2014, 22:33

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.

Events & Promotions

Events & Promotions in June
Open Detailed Calendar

The price of a microchip declines 67% every 6 months. At

  Question banks Downloads My Bookmarks Reviews Important topics  
Author Message
TAGS:
Intern
Intern
User avatar
Joined: 10 Aug 2007
Posts: 22
Followers: 0

Kudos [?]: 3 [0], given: 0

The price of a microchip declines 67% every 6 months. At [#permalink] New post 23 Nov 2007, 01:49
00:00
A
B
C
D
E

Difficulty:

(N/A)

Question Stats:

0% (00:00) correct 0% (00:00) wrong based on 0 sessions
The price of a microchip declines 67% every 6 months. At this rate, approximately how many years will it take for the price of a $81 microchip to reach $1?

a.1.5
b.2
c.3
d.13
e.13.5
Expert Post
CEO
CEO
User avatar
Joined: 17 Nov 2007
Posts: 3571
Concentration: Entrepreneurship, Other
Schools: Chicago (Booth) - Class of 2011
GMAT 1: 750 Q50 V40
Followers: 364

Kudos [?]: 1798 [0], given: 358

GMAT ToolKit User GMAT Tests User Premium Member
 [#permalink] New post 23 Nov 2007, 03:06
Expert's post
2 year.

p1=p0*0.33 ==> pn=p0*(0.33)^n ==>
pn/p0=0.33^n<(0.(3))^n =(1/3)^n

1/81 < 1/3^n

n=4
VP
VP
User avatar
Joined: 08 Jun 2005
Posts: 1157
Followers: 6

Kudos [?]: 116 [0], given: 0

GMAT Tests User
 [#permalink] New post 23 Nov 2007, 03:32
the formula is

X = Amount at begining.

N = No of periods

X*((1/3)^N) ---> since 1^N = 1 then X*(1/3^N)

solve

X = 81 = 3^4

3^4 * (1/3^N) = 1

3^4/3^N = 1

3^(4-N) = 1

N has to be 4 since 3^0 = 1

4*6/12 = 2 ---> two years

the answer is (B)

:)
VP
VP
User avatar
Joined: 08 Jun 2005
Posts: 1157
Followers: 6

Kudos [?]: 116 [0], given: 0

GMAT Tests User
 [#permalink] New post 23 Nov 2007, 03:37
Faster way

81/3 = 27
27/3 = 9
9/3 = 3
3/3 = 1

the answer is still (B)

:)
Senior Manager
Senior Manager
avatar
Joined: 06 Aug 2007
Posts: 370
Followers: 1

Kudos [?]: 21 [0], given: 0

GMAT Tests User
Re: PS-Declining Price [#permalink] New post 23 Nov 2007, 20:41
alohagirl wrote:
The price of a microchip declines 67% every 6 months. At this rate, approximately how many years will it take for the price of a $81 microchip to reach $1?

a.1.5
b.2
c.3
d.13
e.13.5


Here is another way

1 = 81 (1 - 67/100)^2n

1/81 = (1/3)^2n

when n = 2 ==>

(1/3)^4 = 1/81

Hence n = 2 years.
Re: PS-Declining Price   [#permalink] 23 Nov 2007, 20:41
    Similar topics Author Replies Last post
Similar
Topics:
2 Experts publish their posts in the topic In an attempt to abate the pernicious decline in MicroChip's avohden 2 06 Nov 2013, 12:57
6 Experts publish their posts in the topic The price of a chip falls by approximately 67% every year rohanchowdhary 3 16 May 2013, 23:23
ps 6.7 racejockey 2 05 Jul 2011, 21:20
Price of microchip - percentage coelholds 3 28 Jul 2009, 13:16
The price of a microchip declines by 67% every 6 months. At r019h 8 09 Jul 2007, 17:57
Display posts from previous: Sort by

The price of a microchip declines 67% every 6 months. At

  Question banks Downloads My Bookmarks Reviews Important topics  


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

Powered by phpBB © phpBB Group and phpBB SEO

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®.