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

It is currently 22 Oct 2014, 14:31

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

If a sum of money grows to 144/121 times when invested for

  Question banks Downloads My Bookmarks Reviews Important topics  
Author Message
TAGS:
Intern
Intern
avatar
Joined: 10 Nov 2004
Posts: 44
Followers: 1

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

If a sum of money grows to 144/121 times when invested for [#permalink] New post 28 Nov 2004, 11:49
If a sum of money grows to 144/121 times when invested for two years in a scheme where interest is compounded annually, how long will the same sum of money take to treble if invested at the same rate of interest in a scheme where interest is computed using simple interest method? (1) 9 years (2) 22 years (3) 18 years (4) 33 years

Correct Answer - (2)
Manager
Manager
avatar
Joined: 13 Oct 2004
Posts: 239
Followers: 1

Kudos [?]: 6 [0], given: 0

 [#permalink] New post 28 Nov 2004, 17:17
P(1+r)^2 = 144/121 * P
r = 1/11

P+Prt = 3P
P(1+rt) = 3P; rt = 2;
t = 2/(1/11) = 22
Intern
Intern
avatar
Joined: 10 Nov 2004
Posts: 44
Followers: 1

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

 [#permalink] New post 29 Nov 2004, 07:55
can you please explain in more details
Director
Director
User avatar
Joined: 21 Sep 2004
Posts: 619
Followers: 1

Kudos [?]: 5 [0], given: 0

 [#permalink] New post 29 Nov 2004, 08:07
the formula for compound interest is p(1+r)^n
where n=time period
r= rate of interest
p= principal amount

first half of the problem states that if compounded it becomes 141/121 times P

=> p(1 + r/100)^2=144/121P
=>1+r/100= 12/11
therefore, r= 100/11

the second half of the problem states asks for the time need for tripling the amount which would be principal + 2 times the principal.

2P must be from simple interest ( i assume.. correct me if I am wrong)

2P= pnr/100

where r=100/11(from earlier deduction)

therefore, n= 22 years.
Intern
Intern
avatar
Joined: 10 Nov 2004
Posts: 44
Followers: 1

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

 [#permalink] New post 29 Nov 2004, 16:17
I missed the key word "treble" means 3p!

thanks for the explanation
CIO
CIO
User avatar
Joined: 09 Mar 2003
Posts: 466
Followers: 1

Kudos [?]: 27 [0], given: 0

Re: money [#permalink] New post 30 Nov 2004, 09:39
revital wrote:
If a sum of money grows to 144/121 times when invested for two years in a scheme where interest is compounded annually, how long will the same sum of money take to treble if invested at the same rate of interest in a scheme where interest is computed using simple interest method? (1) 9 years (2) 22 years (3) 18 years (4) 33 years

Correct Answer - (2)


I got 22, also. If the interest squared times the original is 144/121, then the interest is 12/11, which means the actual interest is 1/11. so you want to triple the principle by figuring out how many times you should add the product of itself and 1/11 to itself. Meaning, the final equation I got would be p + x([1/11]p) = 3p, and solving for x --> x=22
Re: money   [#permalink] 30 Nov 2004, 09:39
    Similar topics Author Replies Last post
Similar
Topics:
Sep invested a sum of money 3 years ago at 30% simple annual GMATT73 2 19 Feb 2006, 00:35
At the same time, Jane deposited a sum of money at 10% pb_india 6 12 May 2005, 06:17
A sum of money invested for a certain number of years at 8% christoph 2 11 May 2005, 12:32
If a sum of money grows to 144/121 times when invested for christoph 2 11 May 2005, 11:54
Ms. Rose argued that time & money invested in acquiring batliwala 3 01 Nov 2004, 23:38
Display posts from previous: Sort by

If a sum of money grows to 144/121 times when invested for

  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®.